Only issue I have with my two FVM GEVOs (NS Conrail Heritage, and IAIS 513 Rock Island Heritage) compared to any Kato I have is the darned dim ditch lights. Other than that, I wouldn't hesitate to buy another one. Had planned on buying UP 7400 but the ribbon looked more purple to me than it did pink.
That said, I have a good friend that owns Norfolk & Western, Southern, and Nickel Plate Road heritage versions, we mix and match with Kato units all the time, both run TCS decoders. Have never had an issue.
I'm with Ryan on handrails, worst unit I have on the roster is an IM SD40T-2, those handrail refuse to stay on.
Chris