May I jump in here and ask this:
1) ignoring round-tripping,
can I buy/use Motion 5 as a stand-alone to create graphics, render them out THEN import finished projects into FCP7?
2) does M5 recognize M4 projects?
3)does loading M5 DELETE M4 or can they co-exist, like FCP7 and X?
I have not jumped on the FCP X bandwagon just yet and will leave it for a while till it gets the tender attention that it needs to make it a workable editing platform (for me). I am more than happy with FCP 7.