I know there is a ton of articles, guides and forums talking about one simple thing, iPhone 3g slow running iOS 4.x. For the most part, most users say to downgrade from iOS 4.x to 3.1.3 to fix the slowness OR to do a hard reset two or three times. I am not going to ask how to downgrade OR how to perform a hard reset. I have a iPhone 3g running iOS 4.2.1, I jailbroke it using RedsnOw and my baseband is 6.15.00. During the jailbreak operation, I choose to have Multitasking and Wallpaper installed. Of course, I suffer as well with the slowness and Springboard crashing randomly. I have tried almost everything except the multiple hard resets to get the iPhone 3g to feel like it is brand new. I don't have a lot of apps (Winterboard, SBsettings, wallpaper themes, etc...) installed on the phone. I do have Cydia and Cydia related stuff. Someone explain the differences between iOS 3.1.3 and iOS 4.x features? Another words, why should I downgrade to iOS 3.1.3. If I downgrade to 3.1.3 which iOS 4.x features are NOT included in iOS 3.1.3?