Ran the Z yesterday, after a few mods. Found the motor in the rear car was running slower than the one in the locomotive, so I yanked it out and it ran fine. Sorta noisey in the gearboxes, but they have been re-lubed, maybe after a bit more running it will quiet down some, or maybe I won't need a sound system! Need to get the lights back in, getting new ones from Jim Hinds here: http://www.richmondcontrols.com/  He has some neat stuff, MARS lights/etc, all LED's. Two sizes of them also.
Video is here: http://www.youtube.com/watch?v=0EqU57u0L2Q