Park City ? You lucky dog, you. I have a 46 on my Kyosho Cap and it does fine. I think the Kyosho might weigh a bit more than the GP. IT would have to, its kinda chunky. I use an APC 11X5. The 10X6 was awful, just a dog. I've heard of guys using 12xsomething, 4 or 3.75 and getting near 3D vertical. Thats the key to aerobats really, gear it down. You would be surprised how good it would fly with a 46. And the down line is pretty slow to. And you really don't loose that much top end straight and level.

That Saito 82 is the hot one isn't it, the bored out one that is in a smaller case ? I really don't know enough about that one to say.