It seems that every time Apple upgrades iOS we get problems which are then rectified with a maintenance release a few weeks later. This time attention has focused on battery life and on 3G performance with older iPhone 4 devices. Vodafone suggested customers should avoid the upgrade for the time being.
My beef is with battery life. Both my iPhone and iPad have suffered since the installation of 6.1. This is most noticeable on the iPad mini where, before the upgrade, I never ran out of juice during the day. Now, the device is regularly into the red zone by late afternoon. This is subjective, of course, and I have not conducted any scientific tests. But I’ve noticed it and don’t like it.
With luck there will be a maintenance release before the end of February.
by Mike Evans, 10 February 2013