The Under Armour® LooseGear™ Men's Full T-Shirt was designed to keep you cool and dry for your entire work-out. LooseGear™ cools your body by pulling perspiration off of your skin and moving it to the surface where it evaporates from the fabric.
I really like these shirts. I use them both for daily wear and working out. I have not used them on a mountaineering trip or tried wearing them for more than one day so I can't comment on the oder mentioned previously. I have used them for running, gym climbing and strength training w/o experiencing any extra foul smells. Very comfortable and they wick and cool very well. I have more than one and recommend them. I won't using them for any multiday trips or as a base layer.
I've had great experiences with UnderArmour Loose Gear t-shirts (I have three shortsleeve and one longsleeve). I've used them for running, gym, hiking, bike riding, and extensive field use with the military. Their wicking ability is unsurpassed. They are very lightweight, but provide decent sun protection. I haven't had much problem with odor for short-term uses, although after 3 days they are decidedly funky. The smell washes out with no problem, though. The fabric snags easily.