My friend and fellow OGR Forum poster "taycotrains" has some MTH HO equipment. The F unit is of very solid construction. I've seen the G's in operation. They are very impressive. Overall, I'm impressed by MTH's effort in HO thus far. From a standpoint of accuracy, certain MTH HO models are superior to their O scale counterparts.
As seen on this site, it appears some of MTH's O gauge customers feel like jilted lovers because of MTH's efforts in HO. I think if these same people took a really good look at just how good some of the HO models are turning out, they'd have a total meltdown.
Bob