I don't like the 900 degree mode for GT3 because GT3 was never designed to handle 900 degrees. I have owned the mad catz wheel, the logitech driving force wheel, and now I own the DFP. The DFP is by far the best wheel I have driven with, and it was well worth the $150 I paid for it. You can find it online for like $90-100 now, and you can buy them refurbished for $55.
My only complaint is that every once in a while in the middle of the race my wheel stops responding. It usually ends up in me driving off track before I can find the DS2 controller to pause the game. Then you have to unplug the DFP's USB connection and reconnect it. I'm not sure if a lot of people have had this problem or not, but I exchanged my wheel once because of the problem and it still happens. I'm beginning to think it's my PS2 or my game.