IMO, if you have a good non-ff wheel, you should stick with it. Force feedback is good for about 5 minutes as you "ooh and aaah". but for real driving, I find that it gets in the way more than it helps you feel the road. FWIW, I have a Thrustmaster non-ff wheel myself, and I've used Logitech's Formula Force wheels, both new and old versions.
(Old version is a LOT better than the new version. The new one has gears rather than cable for the force motor, which makes them notchy and noisy)
-patchy