After struggling for a little bit with my outdated version 6 of Cubase I checked the demo version of Cubase 7 out of curiosity. I seems to be working fine on Maverics ( I have new MacBookPro with Retina display).
All of the problems with UI are related more to the Retina display, than to the operating system. It’s just that UI behavior is completely different and all of the clicks and other events are processed differently.
If you have Mac computer with normal display (not high resolution Retina) then you shouldn’t expect any problems with UI and mouse. If you have Retina display, then some of the UI elements and menus in Cubase 7 will look kind of crappy, but still usable.
Since Pro Tools 11 isn’t officially supporting MacOS 10.9 yet and users also complain that even the new version of Logic crashes all the time, I would probably try to update to limited version of Cubase 7 for now.
I work in IT and this whole situation with software not functioning properly on recently released versions of different operating systems makes me sick. This is a general complaint, not directed to Steinberg specifically. I’m just very surprised that companies that have been on the market for decades already would not plan at least 1 year ahead and develop and test everything on new operating systems and new hardware instead of releasing wacky “do not yet update your Mac/PC” statements. I bought a new computer with fresh OS installed and I was hoping to buy some software that was compatible, but it looks like I would have to wait for another half a year or more until everyone would catch up.