I bought enough MeUndies to the point where that's the only underwear I own. I have most men's styles in briefs, trunks, and boxers. Not boxer briefs. They are all very comfortable and not restrictive at all.
I bought all size medium in briefs and trunks and I have noticed that some of the sizes are inconsistent with each other. I have at least 4 pairs that fit more like size smalls and 1 that fits more like a size large.
Overall, they are worth the price if you are signed up for their membership.