It depends on what version you are using (I'm using 7.0.8.2) but many folks will say it's better to stick with Nero 6 provided it's one of the later versions like 6.6.0.15. Frankly, I'm not aware of any features version 7 has that the later versions of 6 don't, except maybe proper DVD-R DL support. In other words, "upgrading" isn't always good, especially if you don't need to rock the boat.
-Do you believe you own your computer and shouldn't be told what you can run and do? Then say *NO* to Microsoft Vista!
-Since half the questions here involve media problems, here ya go: Only use Verbatim or Taiyo-Yuden discs (get your TYs from Rima.com, not Supermediastore or meritline). Forget the rest, no matter what "brand" they sell under. Always burn at 4x speed regardless of the speed rating of this discs or your drive. If you have burn problems with these then you have to update your drive's firmware. For double-layer discs, only use Verbatim DVD+R DL and burn them at 2.4x speed.
@others - i use 6.6.0.18 as it's always been bulletproof, i am staying with this version for good as i only burn data/audio cd's and burning of dvd-video discs prepared by DVD Shrink etc