"We used Azazie, and I was very pleased! I've worn the J. Crew BM dresses in the past, which are twice as expensive, and I definitely preferred Azazie. That being said, they're more affordable for a reason -- I would DEFINITELY recommend trying sizes. Most of my girls ordered a size (or 2) up, and then altered the dresses down.
Some weird cons to the dresses are: 1) no clasp at the top of the back zipper, which is not ideal; 2) most of the dresses are ridiculously high cut so a few of my girls had the neckline lowered to be more flattering; 3) the sizes are not consistent from one dress style to the next, which is why the trials are important.
The girls were just as pleased with these as with any other BM dresses, and I think they ended up looking GREAT. Here's a pic to show you (@Ashlei, this is burgundy, but it photographed a bit brighter than it was in person)
ETA: You can see my MOH (in the middle on the right side) is wearing tea length, but the others are all in knee-length -- to give you an idea of the difference."