Well considering most won't outflow the stock TB I say no..but ill let other chime in as well.
You don't need a N* on a genV because of flow you need it because a l67 TB won't fit as far as flow is concerned even turbo guys use a ported l67 TB so to answer the OP original question no you don't need a N* TB and you probably won't see any gains just a different throttle feel
I've never researched the flow numbers between the two. That would be my suggestion and try to get an idea of how much you are flowing.
As for the throttle response, it's there. N* has the tip in made for it. You start off and cruise nicely, go about 30% and you see the thing nearly wide open.