After researching, I had selected a Prodigy. My dealer was including a basic controller with the trailer so I negotiated a higher model; however all they had was the Hayes G2. At first I was really disappointed, but so far I have been really pleased with it. I think it is pretty similar to the P3.
I have towed lighter trailers with the base controllers and they are fine for little trailers - but I wanted something with more feedback for my TT investment. I really like the digital display to tell me my settings, the dial just does not cut it.
One feature that I really like is the boost function in the higher end controllers. What it does is apply a small, but adjustable, amount of braking when the brake pedal is depressed. This is great when you are in stop and go traffic or doing a gradual stop where you are not really braking hard enough to activate the sensors in the controller. I can tell a huge different when it is not activated. What I dont like about boost is you really have to remember to disable it when you are jockeying the trailer around. I was backing one day on mud and when I lightly tapped the brakes it locked the wheels and caused the trailer to slide sideways. I dont forget anymore!
It also has lots of feedback, such as voltage, current, accidental disconnect, etc