Mountain Hardwear Banshee SL 0°

I cannot envision a better product or company. First the product: How could a bag keep you any warmer for the same weight?  

Mountain Hardware has pulled out all of the stops: 800 fill down, hood and a neck baffle, The zipper is covered with a outer flap, and has an inner, down filled baffle.  Conduit SL really adds water resistance to the bag.  The welded seams are strong (though the stitched ones had a problem on one of my bags - more later).  

Overall, it's just an amazing product.  I've never been cold - even at temperatures below rated temperatures (keep in mind, though, I was using the previous model, which was rated to 15degrees.  In my current 0 degree bag, I have not been anywhere below 0 degrees).  

Finally, it is a thing of beauty.  The attention to detail, and the craftsmanship is just amazing.

Now, about the company: I had the original 15 degree bag that I was so happy with.  Perfect fit for my 5'10" frame.  Unfortunately, after a few years of use, it needed a wash.  I followed the wash procedure (front loader, Nikwax "down wash" detergent), and two things happened: several sewn seams split, and the conduit SL coating disintegrated.  

I believed that I had followed all of the recommended procedures, and on the phone Mountain Hardware agreed that Nikwax is OK to use.  Maybe I had a defective bag?  Regardless, Mountain Hardware took care of it for me.  Everyone I talked to in customer support was friendly, helpful and patient... and they made the entire procedure painless.  How many companies do you know that have awesome products and stand behind them like that?  

One final thing... my recommendation: If you decide to wash your bag, try gently hand washing the fabric first (rather than immersing the entire bag).  Getting the down wet may decrease its loft, and washing, is generally hard on a bag (I learned this from subsequent internet research).  In my opinion, this applies to all bags.  

Also, I'd call Mountain Hardware to ask which detergent they recommend the most, as I have concerns that the Nikwax may have been the cause of the Conduit SL disintegration.

Have used this bag on several cold weather camping trips and it has been great. The zero degree (F) rating is right on - even kept me warm with just a 3-season ground pad and 5F temps. Conduit shell repels any wetness you can throw at it without losing any lofting ability. Laminate means no cold spots due to stitching. Plenty of room to roll around (even with extra clothing and a water bottle stuffed inside) and the footbox seems extra roomy.

Only con is the zipper occasionally gets stuck - but doesn't just about every sleeping bag zipper?

I don't like to take a tent when I am trying to go light and have been in rain without getting wet at all. I just put a gore-tex jacket over the hole and stayed totally dry. I have also done winter camping with it and slept with no cave or tent, just on a therma rest pad and stayed warm with no hint of cold spots with tempuratures right around 0.