+4 on the Z4000. With the mix of engines you have, It's the best choice available so you can run them all. Some MTH engines will NOT work with the CW-80. The main problem is the difference in how the bell & whistle voltages are produced. The MTH engines need a DC offset that turns on & off quickly. The CW80 DC offset takes some time to turn on & off, so the MTH electronics do not recognize the offsets.
Go with the Z4000.