Why would you want to change from FCP7? FCPX is a hyped up version iMovie. It's useable, and it's ability to let you work while it auto-renders is cool, but it's really not a professional editing suite.
PP CS6 is great and all, but there's really not THAT much of a difference from FCP7 for the most part. I still use FCP7 almost exclusively, but I'm learning avid. Premier is alright, but I'm just more comfortable with the Final Cut Pro studio stuff.