Perhaps adding a few filters here and there run better on FCPX, but as a full fledged NLE, I would pick Premiere every time. I'm finding rock solid performance, a search tool that *actually searches your metadata* not just keywords, better markers, and the killer feature: Tracks.
Not being trackbased made FCPX a dealbreaker for me, as I use tracks to organize so many things (subtitles, lower 3rds, graphics, singling out clips for effects, etc...).
I like the trim function in FCP, but that was the only thing in the software I found intuitive, and liked.
There are a few things I miss from FCP7 (such as moving clips up and down tracks with Opt-Up arrow) but they're few and far between.
And you can have more than one project open at a time...
So far, and this could change, and I'm shocked I'm saying this, but Premiere CS6 is the editor I was waiting for with FCPX.
Joseph Mastantuono
http://www.goodpost.net
Color Grading & Post Production Consulting