Should I upgrade from my Cervelo road bike to a P2

The correct answer may be found here:

http://www.velominati.com/the-rules/#12

Most of the summer months, I prefer to ride my road bike like a road bike - group rides, canyons, etc.  I picked up a low end tri bike (motobecane) primarily so that I could keep my road bike while training my body to ride steep and low without moving my saddle forward and back, or adding/removing aero bars from my road bike (and without giving my wife grounds for divorce).  For me, this was a wise choice, and although I would like a nice tri rig, I'm not willing to sacrifice my road bike to get one.

If you spend most of your bike time training for tri, "upgrade" to a tri bike.  If you train on the road, but race an occasional tri, you might want to keep going with your current setup (an S2 with the seatpost properly configured and clip-ons is more aero than many dedicated tri bikes).  If you fall in between, keep your road bike and determine what tri bike your budget would let you get away with (or dump the road rig, get the P2, and pick up a cheap road bike).

SYJ