The autopilot from the 50s ended up in the dump decades ago. The current autopilot is "new" but leaves a lot to be desired. Like it was stated before, it will keep you in trim 99% of the time but it has a passive-fail design which can surprise you during A/R (C-17 moving rapidly to the forward envelope is a good example).
WRT KC-46 basing, it is going to go like this. FTU at Altus, too much political momentum. The first operational base will be Fairchild, followed by Pittsburgh and Grand Forks. McConnell will be the last AD base to receive the jet, or maybe just before MacDill for two reasons. 1) McConnell has a ton of jets to replace and 2) McConnell has every single -135 mission. Too many variables to make it efficient.