If you haven't owned a NSX before then I would leave it stock for a few months. The beauty of the NSX is the fact that that it does so many things well. It a great DD, a great cruiser, a great date night car, a great track car and on top of that can almost be a convertible when you want it. It is truely the swiss army knife of cars.
However, the more you mod it the less versatile it becomes. For eg, Taitec LWGT - great exhaust but it is quite loud. This takes away for being a good road trip car, etc etc.
In my situation - I modded my car to be a DE car. Well the cars handles incredibly well but it has a stiff ride, brakes that squeel etc etc. It makes it a not so great DD.