In the past, meaning upgrading the iPhone 3G to iOS4, upgrading the OS version on an older device was a pain. With the lessons learned from the iPhone 3G/iOS4 upgrade, it appears that Apple has learned its lesson. From the various reports, the upgrade is smooth with people experiencing the3200 error the most common issue.

While you cannot get an untethered jailbreak for the iPhone 4 (and no jailbreak at all for the iPhone 4S), you can get an untethered jailbreak and SIM unlock on the 3GS.