When 10.1 arrives I think I will do so in the hope that any issues people have experienced with 10.09 with Mavericks will magically go away with 10.1. It seems logical t me that they should at least begin to.
But here's the question:
Do I upgrade to Mavericks and then FCP10.1 or the the way round?
Installing the new FCPX 10.1 on an old Mountain Lion system then updating to Mavericks seems like it would have increased potential to experience odd issues in the long run. I would say its "best" to do a clean install of Mavericks, then a clean install of FCPX 10.1.
And I would say that because it's exactly what I will do when it's released, but I'm a clean-install-aholic and rarely "update" major changes to the OS or mainly used Apps (I updated to 10.0.9). Instead of updating, a perfectly working System drive goes on the shelf and a newly formatted drive goes in. With good organization and saving of install files and disc images, installing everything is a snap (for example if you still install stuff like FCS 3 from the Discs, you've just got to make disc images and experience the time savings). Of course none of this happens on a production machine until critical workflow elements have been tested with the new software on a secondary Mac.
It's been an evolving process over the last few years, which designed itself out of necessity, reading COW posts, cautiousness and a quest for stability. Seems to cut down on "oddities", that way you only have to deal with actual bugs. Though I've been messing with Mavericks since the betas, it hasn't made it to my main edit suite yet.
On the other hand, the new Mac Pro will ship with Mavericks, so there's really no question. Only choice is to install FCPX 10.1 on Mavericks. ; )