Just my personal observation I find that the Stock Blade CP has a better rotor head than the CP2. Im flying a both helicopters but Im opting out the CP2 rotor head and going with the BladeCP heads. CP2 frame seems to be more fragile(around landing gear points) and so does the rotor head parts. I like the CP2 maingear over BCP. Another thing I find that is lacking is the stock blades on both helicopters. Im finding that the Hummingbird blades are excellent.
The setup I perfer goes sorta like this:
Electronics: about the same (either will do)
Frame: CP2 Best I think overall although may be slightyly more fragile
Motors: about the same
Blades: Hummingbird CNE227 flat bottom (Semi Symetrical)
RotorHead: Stock BCP
Batteries: Lipo 3s 11.1v 1300Mah-1320Mah (helidirect's 19.99 specials)
Doing some experimenting this is the setup that has really worked best for me. Easy to adjust and smooth to fly.