I've had my Sawtooth for about 8 years & have been extremely pleased with it. It's very well designed & super comfy. I haven't had it out in temps below about 25 degrees, but it's been toasty warm for me (a cold sleeper) down to that temp. I love the hood, full length zipper, fat draft tube & independent hood & neck cords (one flat & one round so you can cinch up just the one you need in the middle of the night). Sizing is perfect for larger folks & restless sleepers like me - I'm 6'5", 215 lbs & the Long fits me great. While not as light & compressible as higher-end bags, it still performs very well & is a great deal for the $. In warmer temps, I unzip it halfway & use it as a comforter.
I've been trying hard to justify upgrading to a Marmot Helium, but I just can't bring myself to part with my trusty Sawtooth. Good gear!