Hi Kaz,
To be honest, it seems you are well protected as it is, and there is a danger of overkill by adding more and more utilities that basically do the same job as each other.
Depending on how you use your computer, it shouldn't really become encumbered with rubbish, but if you want a clean up utility, I would recommend
CCleaner, which I use about once a month. If you haven't already, I would also strongly recommend switching to a browser other than Internet Explorer, and would recommend Firefox as a stand alone browser, or SeaMonkey as an all in one browser / email suite, links to both of which can be found in my sig below.
As far as Windows Advisor goes, it does look a bit gimmicky to me, and personally, I would avoid it myself, as it probably doesn't do anything that special.