I was so thrilled to find a sleep bra in my size, as I have never seen one anywhere else before! If anyone could use a comfy, supportive option to lounge around the house in, it's certainly the well-endowed among us. The material is really silky feeling and it doesn't chafe or leave any marks on my skin.
After owning this one for a while, I have a couple of suggestions for things that can be improved. The bra should definitely be a little "taller" like another reviewer suggested. I have a lot of volume in my chest, so the band is obscured underneath my breasts instead of hitting lower across the torso like it does in the picture. A wider band would make it look at LOT more attractive in larger sizes.
As others mentioned, this bra does flatten the chest a little. I actually like this aspect because it makes it more comfortable. The weight of my chest is supported horizontally across my back instead of by the straps, so it doesn't make my shoulders ache like most halters or sports bras without an underwire do.
The problem with the squishing aspect is that the bra spans the space between each breast and does not "tack" against the ribcage like a properly fitting underwire would. On someone like me who has close-set breasts, there is nothing there to separate them from each other and the skin-on-skin contact can create an uncomfortable heat rash. Because of this, I can't sleep on my side or wear it for more than a few hours if the weather's hot or I'm doing something active. If the bra was divided into more distinct cups or there was a little panel of fabric to separate on the interior lining, it would completely eliminate this problem. I could even imagine wearing it to a yoga class!
All of these observations also apply to the racerback tank, as the interior bra is very similar. Overall though, I am very happy to have found something so comfortable for when I need a break from the more serious marvels of engineering, but don't want to go totally braless.