I use NIS 2010 and I noticed something different compared to KIS 2010.
A couple times when I was using MS Publisher 2007 with KIS installed, I always got a message saying that Windows was low on memory and to close any open programs to free up some memory. The only programs I had open was Word, Publisher and sometimes the Snipping Tool built in on Windows 7. I haven't gotten that message since I have been using NIS. I just thought that was interesting.