All of the following is merely my opinion and not directed at anyone in particular.
I believe that the difference in performance between a coupe and a -T is overstated, for the most part. I believe that a truly gifted driver and maybe the really experienced track rats will be able to take advantage of the added rigidity of a coupe. Not most NSX drivers will be able to, however. In the hands of most owners, a coupe will be no faster around the track.
But more importantly, and I think most will kinda agree if they really think about it, if one is able to gain a few seconds on a track, who cares? Does ANYONE here get anything for turning, say, a 1:50.4 instead of, say, a 1:45.8? Will ANYONE here go to a track event and actually think "man, that guy really made a bad decision getting that -T... I was almost 4 seconds a lap faster than him."
I feel the chassis twist in my -T on certain road imperfections and you know what? I really don't think it's so bad that it takes away from my enjoyment. With the top off, the flex can get pretty bad but if I have the top off, I'm not at the track, I'm cruising the streets and enjoying the view out the top.
J