Here's my first blush account , installed easily, quickly and auto updated. I didn't check my commit charge before uninstalling the other three (ZA, AVG, and Spybot) but IIRC it was around 460 and is now 415MB. While a scan is running, appSvc32 process takes about %80 of CPU. From the looks of it, a very small footprint indeed and after I know which processes are which, I'll post it. Hmm, I haven't been infected yet after a full hour!
While I was typing this, the quick scan found one 'threat', a cookie and PC Tuneup deleted a bunch of temporary files along with my browser history which I like to keep a week of. I hope I can turn this function off.
All in all this is a very benign Norton so far, very light on resources and has quite a few config options though I basically just skimmed them at this point.
Specs
A8N-E, AMD64 Venice 3000+, 1GB PC3200.
You can get it
here