I went into a b&m the other day and saw it on the rack. I tried on a 4. I like the fit even though my measurements are off right now. The stomach is a smidge snug but that's my fault; not that of the dress. I'd say the dress fits TTS.
I was concerned about the gathering in the rear:
It didn't poof too much and create extra booty or anything, imo. However, I have straight hips. The dress asked me for a belt. I obliged and tried on the thin patent belt. That didn't work, but it might have been the color. There are no belt loops so the belt has to be right width and fit to work. On the upside the dress has pockets and you can actually use them. You know...some pockets they are adding to dresses are just not really functional. These are.
The dress is definitely a lighterweight wool. This is great in that it will be more warm than a cotton or cotton blend, but for some reason it doesn't look especially dressy. For that reason, I cannot see wearing it tank style as a little black dress. I see wearing it more with a blouse or tissue turtleneck underneath. Or with a cardigan over it. When mine arrives in the mail I will try it with a necklace only, but I expect to want something underneath or over it. This is all from recollect & seen in the tight quarters of a b&m dressing room so we'll have to see when I have it in hand.