I have a few of the Roman Gstrings/Thongs, in the Wet Look Tricot Spandex Fabric, IMO, they run larger, I ordered Large, and if I would have known that the sizing is on the higher end of the size chart, I would have for sure sized down.
Also, I don't care for the Pouch, the Bulge Pouch on them isn't as pronounced as say a Joe Snyder Bulge Thong, or Muscleskin Thong.
I ordered back in 2010, and they have since came out/refined a lot of their styles, so I would for sure try some of the Stuffit line.
Their Gear is Top Quality tho. No janky stitching.