This is an exceptionally subjective (and emotionally charged) question. For some of us the "old school" workflow and style of FCS is important, even crucial. To others the 'iMovie on steriods" style is just as good, even desireable. It very much depends on what you do and how you work.
For me it's FCS all the way, but then I'm just a little indie post guy who has to pay his own bills. I work a lot in Color, which is not supported in FCP X. The alternative color grading systems are out of reach financially. And I've been on FCP for 10 years.
FCX, on the other hand, is getting all the development dollars so it is definitely is the future. And it does some things extraordinarily well. I expect if I was on a field reporting team I'd take FCP X over a hot lunch. In time it may be the standard but right now it's an 8-speed automatic transmission while I need a 4-speed manual transmission with a transfer case and 4-wheel drive.
Take a hard look at FCP X. If you never really got started with your original FCP, it may be just as easy to convert. In the end it will probably be less expensive and better supported as long as your needs match up.
Best of luck