RE: Upgrade CP or get a T-Rex?
I flew my Axe CP stock until I built my T-Rex. Boy am I glad that I did not waste any money on that other heli. I have not even powered it up since I built my T-Rex 450 V2. Get yourself a T-Rex and don't look back. It will be tight getting everything you need for under $1000 if you have to get a lipo charger and balancer. My setup ended up costing me around $1100+tax for the 450 SE V2, DX7, HS-65MGs, Gy401, S9650 and one FlightPower Evo25 2170 lipo. I sold the DS285 servos that came with my DX7 on ebay for $60 and bought another FlightPower pack with the money.
Good luck and have FUN!