An LFS near me, just across the lake in Vermont, has a half circle as their main display tank. Absolutley amazing tank, I just wish they had a nicer reef in it, but it's new and time will tell. Once it fills in, it should be a site to see.
I am not sure about the gallonage though. Theirs is about a 5' diameter and probably about 30", maybe 36" deep. 144 gal???