iPhone 3G. I installed the latest update, 4.whatever, and at first it was OK. But after running it for a few weeks, I notice sluggishness, and in general, I don't like it. I use iTunes and on the updates I always back up the iPhone. Can I use the restore function to take it back to the last version, 3.x? From what I read the back up is just for certain files and settings, not the OS.
Thoughts?

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