I agree with whats been posted already.
The 456, while a great car is a 2+2 and its value will hit the floor soon. The 360 is now being replaced (if not by equal but greater numbers) by the f430 so it, in any form, will depreciate greatly.
I, to be honest, dont understand the 550 vs. 575 (fiorano handling) debate. There must be a driving force behind the 2 models/argumetns (other than the obvious) that Im missing. Maybe someone can clarify (in detail)?! Either way, the 550/575m will not depreciate as bad as the 456 or the 360/spyder.