I'm 5'5", 147lbs, and ordered L and M sizes in this suit because I was in-between sizes and unsure. The size Medium fit me the best; felt like the Medium did a better job of "shaping" my loose curves; the suite has some "give" to it, so might be worth sizing down if you're in between!
What I really liked was that the off-shoulder straps could be warn off-shoulders, on shoulders, or totally off the arms. Removing my arms was super easy, which I could see being helpful if you were avoiding tan lines.
The tie-straps are fine but felt unnecessary because the off-shoulder straps could be warn up or down, and were definitely strong enough to keep the suit up and in place, even in wavy water. I liked one review's idea of cutting the tie straps off completely, I probably would have done this if I had kept the suit.
Ultimately, I decided to return this (for now); I couldn't justify the price for another black one-piece suit, and I was totally adoring a few two-piece suits from my Albion order!
The Wave, Midnight One-Piece Swimsuit
I love, love my swimsuit...fits perfectly! I normally have a hard time finding a one-piece that fits well and looks cute, and this one does!