I've used 30 degree bags for years hiking in the east, but this summer on the Colorado Trail my 30 wasn't cutting it. I ended up switching for an old school 900 fill Marmot Helium, which worked great.
Now it's time to shop for a new bag, perhaps for the Pacific Crest Trail (fingers crossed). I'm looking for a 15 or a 20 degree down fill mummy bag. I'm not completely opposed to quilts, but I haven't been sold on the concept for colder temperatures, and I toss and turn a lot, so I'm not sure I'm the best candidate. I'm 6'2" and pretty skinny, so a snug fit isn't a bad thing.
Right now I'm looking at the Western Mountaineering UltraLite, Feathered Friends Hummingbird, Mountain Hardwear Phantom 15, Marmot Helium, and others.
Recommendations? I'm worried that the UltraLite might actually weigh more than the spec and that the Hummingbird might not be quite as warm as the rating.