i ran my pink steamer tonight & i tried using a mth z-750. it would run good on higher voltages, but the low speed wasn't there. i put my lionel zw 275 back on for power & it ran a lot better at low speeds. i'm not sure why? with the mth z 750 on a slower speed, it would go around a few times then after each time around it would get slower & slower until it would stop, & not always in the same place. with the zw 275, just getting the power on about 6 (soon enought to light the bulb) it would pull & never slow down. i like the horn botton a lot better on my mth z 750, but that's about it. the zw has a sweet spot that i have to find to get the whistle to work.