After all the posts about number plates, bunker-side steps etc it has taken until now to find out that the driving wheels are 1.3mm oversize. An unnecessary error and less easy to correct than the other"faults" that have been raised on this thread.
I'll stick with my two Hornby ones - modifed years ago with Markits wheels, Mashima motor and various mods to the bodywork. And they run very nicely.
Mike