I do use a task killer - it was on the phone GS4G to begin with. I only kill stuff like gallery, telescope apps. Pocket Money, Audubon books. These I installed. And I can delete all pics from gallery and ignore it.
I've found out that apps like FB will collect data in the background. Doubletwist kept opening and I don't trust apps that do that. What's to stop them from setting up an account from your Google/carrier info?
My phone is rooted, just to get rid of bloatware. I would also love to get rid of Google Maps or at least stop it from updating. All I use are my coordinates for astronomical information. Titanium backup is the only app I really would give permission to. I really want to know what the app is updating before I let it.
Go read Firefox forums. Every time FF updates or upgrades, it breaks someone's extensions. There's always a lot of complaints. Windows has buggered scanners, cameras, and other stuff with service packs. So why not wait until the bugs are worked out? And post the information somewhere!
And have the ability to forbid the update. Ask, like Ubuntu does. Google isn't omniscient. If the update doesn't improve the way I use the phone - why bother?
I don't game - so if the update only speeds up graphics for gaming, or if it improves FB connectivity, it's no use to me. Unless it also improves security - which seems to be low on the information list - again, why bother?