I would have called it 3.2. Others have suggested 3.5. A few very charitable souls say 4.0 would be OK.
9 it's not. To me having the version number the same implies functional parity with Archicad, which makes me laugh, but only to keep from crying.
There are precious few interface improvements. One I do appreciate: In Drawing Usage, drawings on the active layout are shown bold. It also has toolbars, and I use the one with Print and Plot on it so I don't have to keep the various interpretations of Cmd+P straight.
The performance of importing drawings is noticeably better, and that is always welcome.
Other than that, it's still a hillbilly. Dragging a copy is still different, the marquee is still different, no split, no adjust, no Info Box, bla bla !@#$% bla.
So let me be the first to dash your hopes that the '9' signifies anything at all. Sorry.
PS, that hotspot glitch, where the hotspots go dumb after you stretch a frame? Not fixed. You can't believe it either!