I know 4.0 almost made the iPhone 3G unusable but heard that later updates (4.1 and 4.2) improved this. If you have a 3G, what are your thoughts? My wife has a 3G on 3.1.2 which is jailbroken. Do you guys think she would get better performance (i.e. speed r reduced lag) by updating to 4.2 and abandoning the jailbreak, moving to a legit iOS3.x.x, or jailbreaking @ 4.1.2?