I love Joe Snyder but agree that the sizing can be inconsistent. One of the first tanga 03 thongs, which I bought in a really nice purple colour - wet look fabric - was looser fitting than subsequent ones I bought as was the purple dazzling bulge thong.
To be honest though and I’ve said this before one of the reasons I love this brand so much, apart from the fact that they tend to be so well made and last well, is I really like the slightly more snug fit of them. I like and get quite aroused from the feel of the strap between my cheeks.