I think you should use whatever you want or need.
Avg 8 incorporates antivirus and antispyware so it is going to use more memory
as it is a much bigger application. To be honest I haven't even tried avg 8.
I don't do suites right now. That may change in the future but for now I have separate
apps to do what I want/need and none hog my system for time/mem and I am very protected.

.
Good luck as one has many, many choices to pick and choose from.

(BTW, superantispyware is a good app. Paid ver is real-time and free is on-demand.
Everything I use, presently, consists of FREE only.

)