Nitrous is a very viable option when loking for horsepower. Most shy away form it because there is a large potential to damage the engine when improperly setup. Nitrous can actually be a great option when looking for a little extra something on the street, whether you're getting on the freeway, hitting a straight on the backroads, or playing with the guy in the vette at the redlight. The good thing about nitrous is you can use it when you want to, you engine is rarely under the added load (unless you always use it).
My recommendation for a street nitrous system is to plan it out thoroughly. Wire in a WOT switch (so it only engages under WOT), wire in an RPM switch (so it only engages above a certain RPM), and wire in a fuel pressure switch (so if you lose fuel pressure for some reason it will disengage rather than lean out your engine and go boom). All of these are great fail-safe methods than can help ensure you won't damage your engine.
Aside from all that its choosing the kit, the shot, plumbing and wiring. I don't know what shot the NSX engines are capable of handling reliably out of the box so research this and be conservative if you are lookng for relible street car. Also, always go with a wet kit (kits that inject nitrous and fuel), dry kits (kits that inject nitrous only) are a waste of time IMO and have more potential to lean out your engine. If you have never plumbed or wired one of the kits, have it done professionally to ensure reliability and an aesthetically appealing installation.
I used not be a fan of nitrous but as I got experience with them I began to see the good in them. There are better routes to go but they are nowhere near as cheap, and when done properly you can have safe, streetable horsepower gains from nitrous.
