Unless your racing I wouldn't get a 450. They're fun and fast but require too much attention and aren't very trail friendly. Don't let people tell you that you don't need reverse. Those are the people that haven't rode a real trail. Reverse has saved me numerous times in many different situations. Do yourself a favor and keep the 660.
I think I am going to go with my gut and not do it, I appreiciate all your opinions. If and when I go with something different I will go with a new 700 or 450 for sure not sure on either yet, will make that decision when the time comes.
The reverse thing never crossed my mind, I think I could live without it but it is nice to have. I rode the 450 a couple of times up and down the street and like it, feels like I could throw it around like it was nothing. But the 660 is alot more comfortable and I don't get to a track very much anymore.