The Lafuma Pro 650 25 degree bag is an excellent ultralight bag. There is no way, however, that I trust this bag to keep me warm in colder weather. I recently used this in the Sierra high country and I would not trust this below 45 to 40 degrees. I also have an older Lafuma warm n' light 800 bag. That bag was rated only to 40 but it has more loft than the Pro 650. Use only in warmer conditions.

i just recently purchased this bag for backpacking - due to its INCREDIBLY light weight (somewhere around 1.5lbs) and it's INCREDIBLY small pack size (11"x5"-ish), this sleeping bag is incredible. it is just about perfect length for me (a thin 6'4) and the half zipper is very nice. the accessory pocket and pullover head are perfect. my only qualm might be questioning the 25degree rating - i would probably guess it to be somewhere around 30/32 - I've woken up at night cold before in it when the temperatures were not below 25. overall, though - an incredibly small, light, and comfortable down bag (pretty affordable, too, compared to other brands' bags)