D67 is right on point. Polo briefs are double lined all the way around, while the swim briefs are just up front. I think the cut is the same, but Turbo's are cut low and have a tighter fit than the more traditional brands (Speedo, etc). I think they look and feel great. If you are a 32, stay with the medium. It will fit you just fine. Like D67 I am a 30, but I am probably closer to a 31, so the medium fits me great.
Let us know what you buy. I have six or seven Turbo suits and would buy all of them if I could
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