I like my baselayers to fit snug - I'm 6' and 180 and the Patagonia Cap 2 T-shirt in a medium fits fantastic. Good length to tuck in or wear out. Wicking capabilities are well....it's Capilene, they are awesome. It does the job it's supposed to. Doesn't stink after wearing it for a few days and dries quickly. I've layered it with a Cap 3 zip neck, synthetic sweater and a shell - no problems in terms of friction between clothing. Not a better base T on the market in my opinion.
Great small locking carab for a daisey chain or setting up an anchor. I wouldn't use this for munter hitches as I prefer something larger like the Rocklock that is more rounded. I keep about four of these on my rack and use them for various tasks -BD makes the best equipment. You can't go wrong with these!
Merino wool is fantastic - this shirt wicks well, is soft and is great for layering. The sleeve length is perfect - I am 6' 180# and I normally wear an XL in other items just to get the body and sleeve length, but this shirt in a Large covers it well. The thumb holes work great, keeping your shirt sleeves into place while wearing gloves and driving tools above your head. The lighter color does stain pretty easily, but who cares - it looks like you were doing something and have a mark to show for it. I'll always take this on my climbs!