Update: the following is obsolete as I have now installed iOS 6. I am holding on to iOS 5 (map issue, "old" hardware with i4). Right now, 45 of my apps are offering updates to iOS 6 but I have not updated on my phone because I am afraid that some may not work well anymore. Should I be concerned, or not? FTR, because of iOS upgrades I lost a $12 app (iDB Pro) that did not follow the iOS upgrade of the time. I want to avoid similar issues.