I've had or shot all three. The P is a great "range" gun. The C is a great "carry" gun if you can get past the lack of capacity and manual of arms. The C2 is pointless - it's only marginally smaller than the P (so it doesn't conceal well - think a G45 sized pistol), doesn't shoot as well as the P, doesn't carry as "flat" as the C.
At this point, I only own a C (my second, sold the first to fund God only knows what, then bought another). Had a C2, shot it, yawned, and sold it. I'd have a P DPO right now if my S2 OR hadn't come in - I doubt, seriously, that the P will do anything for me that the S2 doesn't, at nearly twice the price of the CZ...