I have one with a spartan cab in Conrail colors (Silver Master series with DCC but no sound).
It's a sweet-running engine.. Quiet, smooth, will start moving at very low voltages while on analog DC. On DCC it also runs very nicely.
I don't use it much though, because this puppy has some wicked pilot overhangs on tight curves that yanks the couplers on short cars right behind it sideways and derails them. (Unfortunately I have tight curves because of space constraints).
It comes pretty much ready-to-run. The only parts you have to install are the pilot-end handrails (which requires you to enlarge the mounting holes a bit so the handrail's end-pegs will fit into them) and sunshades.
Great engine.