I'm considering the "REI Nooksack UL +10 Sleeping Bag - Long",---I'm 6'5"----, & wondered how the REI bags hold up & if they're true to their temp.rating? I have a NF Flight +35 bag-----good for late spring, summer, early fall, but want a winter bag preferably down to 0, but doesn't weigh a ton. It seems all the synthetic bags (no , I don't want down,,, allergic to down) that go down to 0 to +10 are in the 3 to 4 lb range. Any other suggestions besides the REI bag are welcomed. Thanks!!