I don't know...with the exception of the builders plates and chains on the rear truck.(Atlas)
I cant see any difference in the cab details between the 2 models I own.
The Atlas is 6880-2 (CNJ)
The MTH is 30-2624-1 (B&O)
Also the Railking one has cut rods on the couplers the Atlas does not.
The Atlas runs horribly in conventional... and only so so with TMCC (it actually has to warm up) then it seems to straiten out ...much better sounds then MTH .
MTH runs great in both conventional and DCS...the sounds are fair.