Yeah, they usually help. I have an ATI R9600P and the ATI Omega's come with a tuner/overclocker. I would suggest going with those for your NV and it should come with a tweaker. Also check GURU, they have a bunch of recommended tweakers including RIVA and Powerstip.
I just used Rage3Dtweak to 'tune' my R9600P to 500/349 for a test comparison to an old post. So yes, I'm pro 'tuning' and pro-omegas (although like I said they are the last one [probably], read my thread about the Omegas)
- You need a licence to buy a gun, but they'll sell anyone a stamp <i>(or internet account)</i> ! <A HREF="http://www.redgreen.com" target="_new"><font color=green>RED</font color=green> <font color=red>GREEN</font color=red></A> GA to SK