Yes, the allison, is generally the choice for the F 650 and F 750, when you go with an auto.
I have 3 trucks, with the engine tranny combo, of an Allison auto push button, and a cat 312 engine.
I think this new 5 speed auto, if built right, will solve Ford's tranny and Diesel problems. However no information is aviable about this current tranny. The current tranny Ford builds, will last and work, if not beat on, and properly maintained.