I have not done any AC commanders, I am converting all of my pullmor to can motors and doing Cruise Commanders.
I am on number 18 ERR upgrade and find it very relaxing, my only snafu so far has been a camelback that refuses to accept data, even with GRJ data kit. The Diesels have all been straight forward (14 of those converted so far, a mix of Williams, Weaver, proto 1 and Lionel).