I’m 5’8” (tall and thin with a larger rib cage and small breasts). Until I tried on the 36AA, I could say that I had never found a bra with wires that fit. I would get actual bruises from every strapless bra that I wore, because I didn't fill the A cups and the wires ended up digging into my breastbone. Strapless bras without wires would quickly work their way down to my hips. Strapless bras are nice to have for certain tops and dresses, so I’ve been looking for one that fits for awhile.
I did have a bit of trouble determining my size at first. When I measured myself according to the Lula Lu website, I easily fit into the AAA cup size (I had someone else measure for a second opinion, too). But, I guess I'm proof that everyone is a bit different. Even after taking out the extra padding, the AAA cup didn't fit. I had a hard time deciding if I should go up a cup size or not. I wasn't visibly spilling over the cups, but they seemed to be resting a little too "low" for comfort. Customer service wasn't able to give me any more information than what was already clearly laid out on their website (which wasn’t enough for me to know what would fit), so I took a risk, guessed I'd be one size up, and paid the extra shipping to try it out.
The 36AA fits much better. The wires are comfortable (no bruises)! It works quite well worn as a regular strapped bra or with an x in the back. The cups are also a close fit, much better than bras I’ve tried on at a regular store. Strapless, it's still not perfect for me (I'm probably in between the AAA and AA, so the bra does start to slip down a bit over time). But, it's the best strapless bra I've owned, so I'm keeping it. Overall I’m satisfied with my purchase.