in my opinion, the best ferraris are v12's in the back. although i do like the 575m, especially with the fiorano handling package.
I have never felt over steer on the street. The track is a different matter. I like them both front and mid engine. I think that a rear engine is more exotic but in some cars they handle poorly on the track. I agree with the statement that the 430 is plenty on the track. Unless it was free and you spent a lot of time on a track, I don't think you would ever fully appreciate all the car could do. If you have to pay the damage to the car including mechanical then I would play it somewhat safe.