I was really scared to get this dress after reading the other reviews.  I'm so glad I took a chance and bought it anyway!  It's wonderful! People complained that the sizing was off, the material was thin and cheap, it didn't look anything like the picture, etc, etc.  I half expected it arrive on fire.  Here's what I think:

Sizing: I don't know for sure, but based on the reviews that complain about the sizing, I'm guessing this is pretty close to one-size-fits-most. There's no tag in the dress with any kind of size, so I'm thinking that if you're around a medium to large in other clothes, this will fit you.  I'm normally a size six, (34 bust, 25 waist, 39 hips) and I ordered the large because I was worried it was going to be smaller based on the reviews.  It fits, but the large is a little big in the bust for me.  It seems like the ladies who ordered the 3X and up complained most about the sizing being off, so I think they send you the same sized dress no matter what you order.  There's some stretch to the fabric, so it'll fit various sizes up to a point.

Material: The material is thin, but not crazy thin.  Personally, I like the weight.  It's soft and flowing, and will stay cool in the heat.  I do have to wear a half slip under it because you can see through the white parts, but the rest covers well.  There were a couple of threads that were left long, but they were easy enough to clip.

Looks like the picture: People complained that it didn't look like the picture, but I think it looks just like it.  Maybe they've changed their supplier after those people left reviews, but I think this is pretty accurate.  The greens are green and the white is a bright white.

All in all, this is a great dress, especially considering the price.  It moves well, it's comfortable, and I can pin the bust or not depending on the level of modesty I need (the picture is not pinned). I'm 5'8" and the large hits right at the top of the foot.