After trying on several styles in Betsey Johnson and b.tempt'd, I decided to branch out and try a 30 band bra in a different brand. Gossard and Parfait both came to mind. After a fellow member of the bra-fitting community contacted me about swapping bras, I decided to switch out my ill-fitting Panache Zara in 28DD for a Gossard Beau Plunge in 30D. The Panache Zara 28DD felt like it was really a 28E or 28F. The wires were too wide and although I filled out the cup at the top, there was empty fabric at the bottom of the cup.
Band Size: Excellent. It is a firm 30 band that stretches to 29.5". It would be good for anyone who is in between 28 and 30 bands.
Cup Shape: This bra is better than most. It has medium wires and the projection is average. After I scooped and swooped I filled out the cup.
Cup Spacing and Centre Gore: Good. The gore is low as it is a plunge bra. It has good cup separation for my far-apart spaced breasts
Verdict: This is 88% a good bra. Go for this bra if you have medium roots, far-apart spaced breasts, are slightly shallow, and have even fullness. I look forward to buying other bras of similar cut in the future.