.......another UP vote for the GP-7 and FM roadswitcher. I run mine on DC and they operate well. The slow speed control is excellent, even on DC. Unlike many locomotives with the so-called, alleged "smart" decoder, it is not necessary to give these two extra throttle then scale it back.
I did manage to fry one of the decoders on DC, though. I have done that to more than one B-mann decoder.