Patrick Inhofer has an excellent piece on the LAFCPUG (Los Angeles Final Cut Users Group) web page, comparing Avid vs. Final Cut Pro 5. It is a thorough examination of the pluses and minuses of the two systems. Conclusion: Avid and FCP are both professional systems; it is the editor who makes the piece wonderful and that can be done on either one. Here's the link:

http://www.lafcpug.org/feature_fcp_vs_avid06.html