I have an '08 P2C and LOVE it. Hard to imagine a better ride. That said, you should read Tom Demerly's (BikeSport Michigan) review of the B12 and B16. The B12 hits just above the price point of an '09 P2C while the B16 is below. The B12 has better specs than the Cervelo I bought (uses Ultegra SL cranks and has the new felt F-bend bars I hear folks talking about.
http://www.bikesportmichigan.com/
And of course aesthetics count, IMHO the B12 is the best looking bike Felt has produced in a while. Still, if I had it to do over again, I think I would go with my P2C (I was in your spot last year, going between a Felt or Cervelo). At this level, I think it comes down to personal preference though. I don't think you could go wrong between the two. Happy Hunting!