ViewSate is page  specific, that's all I can can dream up.
If its page specific then it "probably" uses less of everything and seems somehow seems more temporary and self destroying.

Bit thats just an inner feeling I have, don't quote me !

P.S. I learned everthing I know from the PetShop app which has got it all. If anyones interested I extended it so that "components" can be added by the user from their accounts. It wasn't easy - when you start adding functionality like that you end up having to rewrite lots and lots and lots. The cart itself has to be rewritten quite a lit - to make it todays independant of everything else - so it could be imported. See http://www.aspnetcart.com - I'm going to integrate and reface it with http://cardiffwebdesign.com - maybe I can get a job after that.
Soz to blow my own trumpet but I did good (!) and noones even seen any of it yet - let alone given me a site/job/contract