I've used NU since DOS days. I'm presently running SW2002 on W2K. No problems. My observations, from years of experience:
1. NU 3.** was crap.....I don't think they even got it fixed after almost a dozen patches. Symantec received lotsa grief on their ng on that iteration. Trashed lotsa installs.
2. SW2002. Just install NAV, NU, and CleanSweep. Only run NAV in the background. Run the rest when you want. CleanSweep hasn't even mucked anything up for me.
3. Yeah, Symantec got lotsa crape for the monitoring stuff eating up resources years ago.....rightly so. As bsobel said, NAV doesn't even eat up much on my W2K system......no biggie if I forget to shut it down during gaming or not.....least with W2K. W98SE was affected more with the older versions.
4. As dunkster said, definitely let Disk Dr. replace Scan Disk. And, Speed Disk was so much faster on W9x than defrag.
5. They no longer include Crashmoreguard......which is a good thing.
6. My main complaint is that with each version, it seems to get less intuitive, and a prettier, clunkier interface. Kinda like XP, eh?
--Randy