I just installed Pride resonated TPs and their V2 exhaust. It's an amazing sounding exhaust note. Very mechanical and high pitched - NSX guys liken it to an F1 sound. I haven't posted my own vids, but there are a bunch on YouTube. Those additions should put me to about 270-275whp.
As for the future, I was eventually going to go turbo, but I'm actually very happy with how it drives now. The 6-speed in the NA2 gives the car a much more useable midrange than the 5-speed in the NA1.
And to be honest, I rather enjoy driving a car that I really don't have to worry about mechanically. The TSX was an amazing car to drive and considerably faster in a straight line, but it could be a little finnicky at times. With the NSX, all I do is turn the key and drive. It's plenty fast enough...and the funny thing is that with a car this low (it's REALLY low), 30MPH feels like 60MPH.
Having said all of that...give me a year or two and ask again