I considered buying some Under Armor underwear for a long time, but was always hesitant to fork over the bucks -- they're definitely more expensive than your standard HANES or other brands. The difference is quality, and these things have it in spades. It's the most comfortable stuff I've ever worn, and I'm so impressed with it that I'm taking the time to write this review.
Material was pretty thin, and the sizing is very small. I have a 34 inch waist, and ordered the XL; they were too tight in hips and tighs, and snug in waist. Product should be sized up to be more comfortable.
These are a bit pricey but worth the money. They fit great, feel great and wash well. They seem to hold their elasticity, at least they have so far. They have been washed a couple of times and the fit has not changed. I'm planning on ordering more because it's hard to go back to what I wore before.