I highly recommend this product to any prospective purchaser. It is extremely easy to use (including install), doesn't hog resources, carries out a smarter scan of your PC, can optimize disk performance, and doesn't complain incessantly about backing up data.
I'm an ex Norton360 user who liked the 360 product in most respects but found the interface a bit clunky, and hated all the warnings and notifications that it generated, especially when the status was shown as "at risk" because pc data hadn't been backed up. I didn't want to be told when to back my data up, so when I installed Norton Internet Security 2010 I was pleased that the product didn't have a back-up facility. I wasn't looking forward to the installation - I suspected I would have to go and uninstall Norton 360 manually - but to my delight Norton Internet Security did everything for me with the minimum of mouse clicks, 360 was seamlessly uninstalled and then Internet Security 2010 installed very quickly.
The user interface is smart and intuitive to use and there is a gadget (not as intrusive as 360) that the product installs that shows the system status using an easy to read traffic light.
There are some intelligent features to the software - it can work out which files on your PC pose the most risk and it concentrates on scanning those - files that don't present any risk at all aren't scanned normally - only when a full scan is carried out. The intelligence of this product means that it isn't such a resource hog as Norton 360 - my boot time decreased after I'd installed it. The other bonus is that it seems to do more in the background without bothering to push out a stream of notifications. Oh yes, it works with Windows 7 too. And in a full week of use I've had no crashes at all. Fantastic
All in all, this is the best Norton product I've used - it includes Virus protection - including something called "pulse updates" which gives up-to-the-minute protection, email filtering, website threat analysis, network security features, phishing detection/blocking, login and personal data management, hacking protection, system tune-up tools.
Highly recommended and this is a good deal, considering you get three licences.