I just wore this for the first time this morning to do a yoga flow/barre-style workout, and it worked great for that purpose!  It's made of that super nice and thick cotton that Beyond Yoga uses for their products, and is super comfortable to wear.

It's also got a nice amount of stretch to it so that it's easy to put on.  (I hate pullover bras that make me pull a muscle trying to get them over my head!)

As far as support goes, I wouldn't recommend using this for any medium- or high-impact workouts, but for yoga routines it works great.  (It kept everything in place during my down dogs this morning!)  Just be warned that it is just as low cut as it is in the photo, and, because of the removable pads, creates some serious cleavage.  I work out at home so that's not an issue, but it would be too revealing for me personally to wear out.

The sizing also seems true to size.  I wear a 32D (or 34C in my "sister size"), and the size small fits perfectly.

I may need to pick up another one of these!