This is just my personal opinion based only on upgrading my iPhone 4 and iPad 2 to iOS 5.0, but I'd be curious to compare with others' experiences. To get a smooth, nearly ideal install: 1) Click on "Apps" in iTunes and download all updates. 2) Once those downloads have finished, sync your device. 3) Once the device has synced, after all apps are fully updated, right-click your device and click "Backup." (do it twice for sharts and giggles) 4) Now go into the settings tab under your device on iTunes and click "update now." 5) (maybe not important) Don't let your computer sleep/hibernate during the upgrade process. Again, I only have two data points to compare here, but my iPhone update was a nightmare (iTunes froze completely multiple times, it couldn't find my most recent backup, ended up restoring as a new device). With my iPad, it was perfect. On the phone, I was actually midway through syncing and had only partially downloaded app updates when I clicked the "Update Now" button under Settings and started the iOS update. I'd be curious to see if others agree/disagree with my assessment. Could all be voodoo hocus pocus,... try for yourself and let me know.