Like many of you here, I've accepted my obsession with trying and collecting different underwear. For background, I've been on a journey of losing 100lbs and getting into shape (best shape of my life at 51). As part of that, I found myself shifting underwear styles and went from almost exclusively boxer briefs to pretty much only briefs, bikini briefs, and thongs.
On to the reviews:
Sheath briefs (both American and European cuts): Not sure how I found these, other than Google's algorithms knowing what I might like. They are a little pricey, but I'm impressed so far. So much so that I went back and bought a couple more pairs. First off, the material on these is premium. I love the thickness, while being smooth, soft, and breathable. I wear a large and these fit great. The pouch accentuation is a bit less than something like RMAC, but they are still comfortable. The dual chamber system is interesting and I like it. It seems to work better than the Separatec ones I have. Even as more of a grower than a shower, these work fine for me. The American cut is more boxy, I guess, while the European cut is a little closer to Bikini brief (although definitely not a bikini brief). I like both and I actually like the plain white versions. There's something oddly sexy about having underwear that looks kind of like a tighty whitey, but much more flattering, comfortable, and higher quality.
RMAC modal bikini briefs: I love these and they may be my new favorite bikini brief. The modal fabric is soft and breathable. Very comfortable. I'm a large waist with a B pouch and the fit is perfect. The accentuation of the pouch is great, and my wife definitely appreciated them. I got the limited edition red, white, and blue pack. Not a ton more to say about these, I highly recommend them.
Both of these brands are now in my regular rotation. I also love the RMAC premium V fly briefs and their thongs. Their thongs were the first truly comfortable thongs that I have owned. I need to try their new seamless thongs, once the budget allows for it. Sheath are also up there with Krakatoa for me now as my favorite briefs (plus the RMAC ones).