My CP still has the 4-1 but has 370-9T, heat sinks, Li-Po's, and Bell-Hiller. It's only missing the TX/RX/3-1 from being a Pro. Since I can't go outside...pretty limited on testing the Pro outside. As far as indoor hovering goes, my CP and the Pro hover about equal in stability (almost hands off). Stands to reason...I set them both up so they will fly the same. I haven't tried the idle-up on the Pro yet...that will wait for outside. Personally...the difference is the Bell-Hiller upgrade. It just makes things more responsive and it seemed to improve stability a bit. So I have an extensively modified Blade CP, and a CP-Pro. My CP flies a lot better than a stock CP because it's nearly a CP-Pro anyway. Wheeeeeeeeeeeeee! CP-Pro!