Mickey,
I think there is no real need to switch to Leopard at all!
It was not specifically designed for video editing and Apple
had to take into account possible glitches and compatibilities issues with over 30 software of
its own make.
Well, there might be some improvement in how RAM are used but FCP will still need less than 4 GB of RAM to work.
As you perfectly know so far we haven't had reports of remarkably improved performance (rather the opposite)however, it is now clear that a clean install will less likely bring issues to users.
After waiting for reports on how FCP6 runs on 10.5 now it is time to wait again and see if 10.5.1 will bring some sunshine and put an end to these murky days!
See [this thread|http://discussions.apple.com/thread.jspa?messageID=5657107�]
It is not that old.
Non-answers actually can be considered answers too! Maybe good answers!
Good luck with your choice!
Gogi