Oh baby, comfort! Got this on SAC for cheap, ripped it open, put it on and was amazed at how comfortable it was. Extremely stretchy but not baggy. Broke it in the next week by wearing it on a 3 day backpacking trip in the Black Hills. It's not so techy that it keeps the mosquitos at bay or the funk away, but it wasn't designed to do either. Got it in grey and had to wash it twice with some stain remover to get rid of three days of trail grime, but it did come clean in the end. Medium fits all 6'2'', 156lbs of me awesome. In the end I'd buy it just because it's comfortable and you can where it for "whatevering" (it says that on the Sport Science tags, which, if you ask me, is extremely dorky).
This is my first official base layer of any sort (and first icebreaker product) and I've been wearing it consistently since I got it about a month ago while on a fishing trip to Eli, Minnesota (splurged and got it full-price whereas the wife got a rediculously expensive (for us being poor people) North Face pull-over sweater thingy - no tech, just style for her). The fishing certainly sucked (2 walleye, a small mouth bass, and 1 small Northern - just enough for a fish fry for four), but the BodyFit 200 kept me nice and warm with only my Salomon softshell over it most of the time, even though the last three days of fishing on the open water meant 50 degree weather and 30 mph winds. Brrr! Don't regret buying...get it on SAC or Backcountry if you can. Color (dark brown for me) looks great. The size medium fits all 6'2'' and 156lbs of me awesome (think roadie riding jersey fit) - not even too tight under the arms. Plenty of stretch for getting into and out of. Washed it for the first time this morning and it came out looking great (regular detergent with like colors in cool/cold water - hang dry). And like I said, I just washed it for the first time after a month and stink it did not - my wife never said a thing. Never had anything wool comfortable enough that I'd choose to wear it next to my skin. Especially loved the "baa-code" that lets you meet the sheep that donated it's winter coat to help make the shirt - though I haven't met "Smeagol" as I shall name the spry New Zealand sheepy who was my donor. All in all - keeps you warm or cool (and comfortable) as needed.
I'm 6'2" and I have a small thermarest (different model, but the same length and width) and I can live with my feet hanging off the end (never get cold, but then I haven't really gone below maybe 40 degrees). A problem I have run into though that does bug me but may not be any concern to you since I am taller, is my knees don't fit on the pad, which I find quite uncomforable, especially since I am usually a side or stomach sleeper. I'd probably go for the medium if I were you and just bring one less pair of underwear if you are concerned about weight... you're going to smell bad anyway!
I got this jersey on sale from a bike shop about a year ago and I think I have worn it more often than anything else I own...and I don't even think I've worn it riding (two jobs makes for not a whole lot of ride time)! The jersey has an athletic cut, is definitely pretty soft and really freakin' comfortable - thus the wearing of it so often. I'm 6'2'', 155lbs and the large fits perfectly. I wear it as base layer skiing and on really cold days. If you can get it on SAC do it, if you can't, get it on backcountry!