I've also had excellent results with Parelli -- seems like the best program for dominant/high energy horses particularly in combination with newer riders/owners.
I have a little Arabian gelding who is 10 now. We're slowly recovering from the classic mistake: green (untrained/unexperienced) horse + green (untrained/unexperienced) rider/handler combo. If you're considering horses --- don't do this! LOL I thought I'd be fine since I had a trainer at hand but ultimately wound up firing the trainer and switching to Parelli's program before I started to really have fun and get anywhere with him. Though, from a permaculture perspective, he's not very multi-functional since he'll never do much more practical than produce poop and amuse me! =)