On the BTD website, it says that:
6 mm antique cushion cut: 1.25 carats
6.5 mm antique cushion: 1.5 carats
6 mm regular cushion: 1.0 carat
6.5 mm regular cushion: 1.5 carat
So if you order an Asha from BTD, you know what you're getting, exactly and will know what to tell people. Depends on the cut you choose. I vote for the regular cushion, but that's because it's more popular right now, people have seen it, and it has lots of the "pinpoint" sparkles of light
Good luck! Let us know what you choose!