Sizing: band is accurate, cups also seem about right. The main problem for me is that I am a 40 G (or F, depending on US or UK measure), so a 42DDD is equivalent in cup size to the 40 G, but it is too large in the band. I was hoping the band would be a bit small so I could get a less expensive sport bra than some of the others, but that's not the case.
Support: I ordered 3 sport bras: Luniare, Bendon, and Panache. Wearing each for about an hour or so, they seem about the same. Any bra in a larger cup size is going to have some bounce; this one does have some but all in all, is does well. If I had a smaller band size, I imagine I'd have even less (but then the cups wouldn't fit).
Fit: The straps can be adjusted to be really long; I normally have to adjust all the way, but when I did that with this one, the band was much too low and hurt. After moving the straps several inches tighter, it was much better. The very bottom of the band is a bit scratchy and I can still tell I'm wearing it an hour after putting it on. Not sure if that will go away with washing. As others have said, the cups are more the old Playtex style in terms of shaping: up and out. In a heavy cotton t-shirt I can see the lines. If I was working out, I might not care as long as I was supported, but it would influence my decision to wear it in any other circumstance.
Annie from Chicago/IL/USA