I have run the Z4000 through its paces. I feel it is a fine
transformer. It packs plenty of power. Trains fly around the track. I
have run older as well as newer engines; (all generations of MTH, Lionel
pre and post war, Williams and Weaver) all run fine.
Protosounds are a snap to access with its easy user interface.
I had one slight problem/misunderstanding with it. MTH was quick to
address my problem. The told me what to do and it fixed it. I can not
see where one could buy a more powerful or user friendly transformer. I
recommend the Z4000 highly.