Im going to disagree with Ab. Even though I dont own a 512, I have a Testarossa and for me the Diablo is the more comfortable of the two to drive. In the Testarossa you adopt this weird seating position because the seat doesnt go far enough back. The Diablo trans, brakes, shifter etc are all better than the TR, although my Diablo is a 98 with power steering etc. That being said I previously owned two other Diablos, one a 92, and another 98. All my Diablos have been pretty much trouble free , whereas even if the Testarossa was just as trouble free, it would lose due to the belt service. On top of that, the Diablo is night and day in excitement to drive.