Longitude Montego Bay X-Back One Piece Swimsuit

I'm 5'10" with a BMI of 20 (normal weight range) and I usually wear a size 4 in pants and a size 6 in tops. I have quite a long torso, about 2" longer than average from shoulder to hip, and was hoping that Longitude's "long torso" swimsuits might be a good fit. But I've tried this swimsuit in several different sizes now and have concluded that Longitude suits, or at least this suit, is not designed for long torsos at all but for "wide" torsos if you get my drift. Sizes 4, 6 and 8 were INCREDIBLY tight from top to bottom - the shoulder straps cut into my shoulders very painfully and the crotch was so tight it felt like a knife. The suit was literally too short. Size 12 finally turned out to have the right torso length, but at that point the suit starts getting very baggy - there were loose baggy folds of fabric all over my stomach and butt. Really unflattering! I think this suit would work well for a heavier swimmer of normal height, but it's not actually for tall, truly long-torsoed, swimmers at all. :(

I'm 5'10", 140 lbs. I wear a size 4 or 6 in pants and dresses, but thought I'd better size up for a swimsuit so I ordered a 8. It was astonishingly short on me for a so-called "long torso" suit! It was so tight from shoulders to crotch that I almost couldn't straighten up. I think by "long" they must mean... like... no more than a 1" longer torso than average? (I'm about 2.5" longer than average, from point of shoulder to point of hip). So, size up A LOT if you're tall. I do like the suit otherwise though and have ordered a size 12 to give it one more shot.