David, i bow down to nothing, unless its worth bowing down to. I have owned a Testarossa, and i have owned 2 Nsx's. An early model Testarossa will be neck and neck with a Early Nsx from a dead stop to 100mph. From a roll, say 30mph in first gear, the Testarossa will walk away from the Nsx. On the highway, the Testarossa will kill an early Nsx. I have been in this secenario several times, both in my cars, and in others.
As for a 512tr and a 3.2 Nsx, i dont know. Havent owned either, but my money, especially from a roll, would be on the 512Tr. To 100, i believe it would be close from a dead stop. I never said the Testarossa was a racecar, neither is the Nsx. The brakes on the Testarossa also suck.
As for maintenence, they are not that bad, find one that the belt maintenence has recently been done and youll be ok. Also, clutchs lasting 2,000 miles is also bullcrap. I know people with over 25,000 miles on stock clutches.
Best thing to do, buy what YOU want, not what other people want. Buy on your own opinions, not others.