I've always felt that when people talk about FCPX being fast, they're really just comparing it to FCP 7, not necessarily Avid or Premiere.
I haven't really played with the newest version of premiere, but it's been 64 bit for awhile now, making good use of the mulitple cores. Avid has always felt fast from an editing point of view (with the exception of loading the project, and drawing waveforms).
I could get good performance out of 7, but really that's due to best practices rather than an inherent speed in the program. You learn to work without waveforms, or filmstrip view, or too many sequences. You break up projects to keep down project bloat and keep load speeds down.
In FCPX, filmstrip view and waveforms are on all the time and it still feels pretty snappy overall.
Andy
http://www.timesavertutorials.com
