Hello Matt. I currently have 3 MTH engines. Pennsy K4, SP Daylight and an Erie Triplex (sold out immediately after release). All run flawlessly. I am considering the move to Ho from O Gauge because of space limitations and only considered doing so now that MTH engines have all of the features that I have come to love in O gauge engines ( sound, smoke, die cast bodies in their steam engines, etc). They also perform all of these functions under DCC.
Go to their website to learn more about their HO "trains that do more".