I don't know about you, but I'm really keen on doing really short bursts of activity and getting instant feedback.
I'd rather install 15 packages separately if they are substantial downloads than wait for them to all go at once. Infact, I'd often want to only install 3 or 4 and ignore others until later.
Its for that reason that the ubuntu update manager drives me nuts, and to the command line. If it had a 'select all/select none' toggle, I could easily clear the default select all, and life would be better.
So where do I go to whinge about this, and how do I do it?