Arc'teryx Thorium Hoody

The Thorium AR does exactly what it intends to, which is keep you very very warm and comfortable for a low weight penalty. Buy this jacket if you want a near a perfect insulation layer for weather below -5°C (23°F) that packs small and feels like wearing a cloud.

First things first, this jacket excels at its intended use. If it's cold but dry, it's great. If it's wet or the wind picks up you WILL need a shell over it (down + water = bad, it isn't incredibly wind resistant). It's designed to be worn over a baselayer and under a shell, during low to no activity. If you're huffing up a mountain you'll need to take it off and rely on your shell and baselayer. It's designed to keep you warm when you stop for a break, make camp, or are in -25C/-13F and below. Basically if you're sweating, take it off, if you're cold put it on.

Also of note, this won't keep much of your butt or legs warm. If you're out in weather cold enough to need this you should have two layers on your legs (two out of three of long johns, pant, or soft/hard shell), or on a short fair weather commute with only a t-shirt on under it.

Warmth:
City commute (20min walk, 20min waiting for bus, 20min walk):
-30°C/-22°F and above with only a t-shirt on under it, along with toque, mitts, and windshell pants and I'm toasty. If it's colder, or wet, I throw a shell on over it. It is really, really warm. -30°C-ish with only a t-shirt under is pretty impressive.

• Above -15C/5F I wear it with jeans and a T-shirt. 
• Above -5C/23F I switch to my shell and a light fleece.

In the backcountry, I wear a baselayer and shell on the go, and add this when I stop or the temp drops significantly and I'm too cold in the shell/baselayer. It comes with me and works perfectly from -5C/23F down to -40C/-40F, working alongside mitts, toque, long johns, shell pants, a 200wt merino baselayer, and a hardshell jacket. I carry a (very) light fleece for on the go hiking as well if weather requires it, as the Thorium doesn't breathe very well for high output activity.

To my knowledge it's one of the warmest for the weight on the market, and strikes a perfect balance for really cold areas. Lighter puffies tend to be a bit too cold to use with only a shell and baselayer (or T-shirt in town). Heavier jackets are pointless, as this is warm enough for a -30C/-22F hour long belay with shell over it. If you live somewhere where it rarely/never drops below -10C/14F, maybe look for a lighter puffy, or aim for a fleece.

Fit:
Awesome. I'm about 5'11" (180cm), and 160 lbs with long arms and shoulders somewhere between beanpole and broad. The fit is near perfect, with full range of movement and no pulling.

The sleeves are long enough and stay put with a well designed elastic cuff (I was surprised how much I like it, figured it wouldn't be as good as adjustable velcro cuffs).

The hood is snug and mostly stays out of your line of sight. It is very warm, and fits ok under a helmet. Once zipped all the way up it stays put without any adjustment. Not keen on the fact that the hood can't be pulled on/off without unzipping, but that's a pretty minor annoyance.

The bottom has an elastic pull to block out drafts, which works as intended. Between the cuffs, bottom elastic draw, and collar you'll be in a toasty cocoon with no drafts.

The zippers are smooth and high quality, and I've yet to have them catch.

It suffers from same problem all men's outdoors wear seems to have, which is enough material/zipper to cover a beer gut if you happen to have one. This leads to a slight "zipper paunch" which is mildly annoying if you're skinny. Arc'teryx's stuff seems to be a bit trimmer than its competitors though, and it isn't as pronounced in this jacket as most others I've tried. It's definitely one of the trimmest I've worn with exactly enough excess material. If you have a beer gut, it's great aha.

The jacket layers exceptionally well, with room below it without being too boxy/bit. It fits nicely under a shell, and has slick enough fabric that your layers won't bind.

I've had this puffy for three years, and it's one of my favorite pieces of clothing/gear. It's so comfy you're actually excited when you get to wear it. The attention to detail is also incredible, every stitch is perfect. I love this jacket in a way you can't understand until you've owned a really high quality puffy.

Weather proofing/breathability:
While it's great on its own on clear days, if you see clouds you'd best bring a shell. It can resist a bit of drizzle or snow, but not for prolonged periods. If it gets wet you're in trouble, so don't go swimming in it.

The puffy breathes better than I have any right to expect, but you certainly won't be hiking in it for more than a few minutes. If you're sweating you'll have to take it off, or end up swampy. It's a bit unpleasant against bare wet skin as well.

It is not intended to be worn on the go though, so these shouldn't be real issues...

Durability:
It isn't made of iron, but you don't have to baby it either. The fabric is waaay tougher than you'd think when you hold it. No holes yet. That being said, keep it way away from fire, or well protected under a shell. Sparks will burn instant holes, through which you'll quickly lose down. After three years of heavy use (daily commute during the winter, plus snowshoeing and mountain hiking on most weekends).

Weight/Packability:
Packs down to smaller than a Nalgene bottle into its own pocket. It weighs next to nothing. The pockets are big enough to store your gloves, but are a bit tight for large mitts (they will fit without jamming them in though). It's more than worth its weight when winter hiking, even if you're aiming for that ultralight baseweight.

Comparison:
Lighter puffies are not warm enough in my opinion (if you're warm enough that a lighter puffy is enough, a light fleece, baselayer, and a shell should be enough (in which case they also breathe better than a puffy). This puffy is perfect for its purpose. This jacket is as good or better quality than everything on the market. I spent a lot of time shopping around, and talking to fellow outdoor enthusiasts. Happy to say it was the right choice.

If you're an active outdoors sort, it is very much worth investing in a high quality puffy like the Thorium AR, and  high quality baselayers (long johns and long sleeve top). These are three places you will never, ever, regret spending extra money (even if you're a cheap-wad like me).

Disclaimer: I got this for 40% off at a retail store as part of an inventory shift event. It's pretty pricey at full price. That being said, if it was stolen, I would immediately buy a new one to replace it, even at full price. Even someone as stingy as me is willing to spend for this quality.

A very durable, exceptionally warm hoody that excels in the right conditions.

One of the perks of your friends knowing you like to walk in the dirt is gift cards. I'm not prone to dropping 300 bucks on a jacket but having moved to the mountains and wanting a piece I could wear both on the trail (in the right conditions) and day to day I pulled the trigger on the Arc'teryx Thorium AR. (On sale)

Score.

I own a couple of other Arc'teryx pieces and so I assumed the quality, durability, and fit would be there. I wasn't wrong. A lot of gear companies are all over the place with their sizing but Arc' seems to nail it every time. I'm 6', about 185 and the Large was the right call. Perfect sleeve and hem length, no binding anywhere, a clean fit throughout with enough room to wear over a base and midlayer. This falls under the "Regular Fit" for Arc'teryx sizing.

The hem drawcord stays locked and eliminates drafts, the hood is adjustable and offers excellent coverage without blocking vision and the zipper runs smoothly and high—offering a chin guard that ends at the nose. My understanding is Arc'teryx updated the zipper, which can easily be handled with gloves, to insure it stayed in place where you wanted it. The zippered handpockets are deep enough and, while not lined, still keep the digits warm.

There is one internal, zippered pocket that includes the attached 2.5 L stuff sack. Personally I'm not a fan and prefer larger, deeper pockets such as on the Outdoor Research Transcendent. It will hold liner gloves, a phone, or other small items but is too small for gloves and mitts. I'd also like the option of being able to remove the stuff sack.

The fabric (with a reasonably effective DWR coating) is a very durable 30D nylon that almost has a stiffness to it. It's not comparable to most lightweight puffies but it's not designed for the same conditions. This one is all about warmth, durability and protection.

The Thorium is PACKED with a 750 fill of goose down (responsibly sourced) and while it doesn't give off the Michelin Man vibe it's also not a down sweater. I've been amazed at how few feathers I've lost as I know Arc'teryx overstuffs to compensate for that.

An interesting feature is that it uses Coreloft synthetic insulation in areas prone to moisture like the cuffs, the armpits and hood. In all honesty I haven't noticed any dramatic difference in those areas.

The jacket comes in at about 17 ounces which is heavier than most in the space but not outrageous. I have a couple of other puffies I turn to first unless temps are in the teens. It doesn't pack particularly small and, for me, it's too warm to wear while moving in anything over 20 degrees or so.

I absolutely bring it along on snowy day hikes and overnights when I know it'll be extra chilly. You slip it on when you stop and it's like you've entered in to a different hemisphere. The coldest I've had it out when I've been moving was about -5° and I was perfectly comfy with a baselayer and fleece. The other side of this jacket is that it just looks good. It's the only piece of gear I own that I'll also wear out and about. I figure I'll get my $300 worth until the Tenacious Tape makes its inevitable appearance. But given the fabric strength that might take a while.

So IF the conditions call for it the Thorium is a rock solid choice. Might work OK for some who get cold easily in the spring and fall, but I see this is a pretty dedicated winter piece.

Good fit, warm.

Jacket is comfortable and warm as outer layer without midlayer to 4-5C.

Problem with leakage of feather through inner lining brought to attention of Arc'teryx shortly after purchasing and advised this was normal initially but would disappear with use. Have now worn for three winters and feathers still leaking through inner lining when wearing light wool sweater.