I use the First Lite merino wool boxers. But I am into cutting weight, so someone post the specs on rye's underwear. I am guessing I could trim some of that extra material off if I don't need it also.
The First Lite boxers for me have never stretched out or lost their form. They actually fit like boxer briefs, which are perfect for me. No chaffing issues either.
Obviously I am not a guy, so the specs will vary some, but I have been very happy with merino wool briefs by icebreaker. I wore synthetics by Ex officio for several seasons and while they dry quickly they get a funk after a day or two. Wool is nearly stink free, and if I bring a spare pair along I can wash one in a creek and dry them out over the brush in an hour or two. I won't wear cotton or synthetics in the field again...
I just got my first lite merino wool boxers in the mail today. I tried them on and they are very comfortable. Hopefully they are funk free like they say they are cause we all know how well you can smell being in the backcountry for a week at a time. Rye, is that a thong or a full cut back cause I'm in for a pair if they are a thong.
I have a few pair of UA, but I prefer some Starter synthetics I found at Walmart for $10. They are more comfortable, and don't get as funky as fast as the UA. Plus they are half the price. I would like to try some merino, but they are pretty expensive.
Merino Wool, Red Desert's from First Lite are amazing... I can't imagine how bad the UA stuff would stink after a few days given how bad their shirts smell after a few hours of hiking...