Usually I always like to keep my software and OS up to date, but I use SketchUp practically every day (along with Maxwell Render) and so this is a concern. I've been quite content with Mountain Lion so if there were issues with SketchUp running with Mavericks I could wait until things were ironed out.
That said I've been reading reviews of Mavericks and most of the changes are apparently "under the hood" so to speak in terms of efficiency and performance. Thankfully the user interface has been tweaked but not changed and not as drastically as iOs7 on iPad and iPhone. I'm glad for although my mobile devices do work a bit better I don't care for the look of the iOs7 user interface with its simplistic and cartoony looking icons and such. StilL, I am getting used to it.
I've gotten quite comfortable with SketchUp and am learning to do things I would have found daunting when I first started. I also feel a bit spoiled because after some small frustrations getting started I now feel it would be a chore to learn how to use another 3D program that, to me, seem overly complex.
I know I'm still not using SketchUp to its full potential and that there are likely plugins that could sometimes make things easier for me in certain tasks, but it's obviously a continuous learning process. I'm using the free version with an upgrade of Maxwell Render (it was only $99 at the time) so there are certain Pro functions unavailable to me. One thing I'd really like to be able to do would be to export really nice 2D line drawings/graphics of my models (I design my own science fiction hardware and spacecraft)---the reverse of importing CAD like drawings.
Anyway for now I'll wait to hear more about compatibility before installing Mavericks.