If similar to the 3A, I would go TTS in shirt sizing or one up. That's my experience with the 2 3As I got. For example, my 52 3A is great. And that would be one up from shirt size 50 (25" p2p). Better still I would go for a size 50 since alot of my shirts are 48 (24" p2p). Ziss was awesome. But not sure what the gripe was with the retailer. IME, I got my sweaters, they were true to measurements, one turned out too big (way too fucking big) but that was entirely my fault, and I paid not a penny in customs fees. I couldn't ask for more. If they carry my size in the 6A, I'll order from them again.