Thanks. I spend a lot of time reading posts at backpackinglight.com. They have some guys there that get very technical about different materials, clo values, drying times, etc. Most of them prefer standard 100wt fleeces over the r1, claiming they're both warmer and dry quicker. I find the R1 more comfortable but haven't worn either in demanding enough conditions to pass judgment. I do know my North Face TK100's are 2-3oz lighter so once of those are more likely to make the packing list if I was inclined bring a mid layer on one of my backpacking trips.
