Coming soon.... a look at how i updated to Mavericks and FCPX 10.1 while in the middle of a feature edit. Yes... a 97min timeline with multiple 3rd party plug-ins and more compound clips than you can shake a stick at, all moved flawlessly to 10.1.
I'll go over how i made the move safely and with the minimum of stress.
It has to said... this was a very worthwhile move. Updating NLEs in the middle of a big project is generally a no no... but this worked and the speed of and ease of use of 10.1 compared to 10.0.9 makes it well worth it.