"+For me 80 MB is huge. ... There are many many people out there in isolated regions of the world that don't have ADSL.+"
For your specific situation, your perspective is correct. Unfortunately, that ship has sailed as the vast majority of computer users have some access to high-speed internet. Companies are naturally aiming their work at those who may be 'more current' with technology. This is not to minimize your situation, but to put it into relative perspective.
"+You say full updates afford better control over install than patches. What do you base these comments on? Surely a patch is just a program designed to amend a part of the codbase. Firefox manages to update this way, and I think quite successfully too.+"
I am basing my statements on:
a) My limited IT programming skills in developing small software solutions for clients
b) The several responses here on these Discussion by true IT professionals who have cogently explained the reason for preferring full updates rather than patches
Realize that Firefox is a 7-8MB program in its entirety. Compared to iTunes at 10x the size, I would assume that the complexity of Firefox is significantly lower than the functionality underlying iTunes. I will not even begin to speculate as to the
practical ease of releasing iTunes patches (even though the conceptual idea appears quite 'simple').
Lastly, I have seen maybe 10 Threads on your issue over the past 4 years. Ignoring the 'me-too' replies once someone has thrown out this 'issue', that's such a small amount that I cannot foresee Apple changing it's update model. But - you can always send Apple your feedback as provided in one of the posts above.
Best of Luck