I can only speak for N-scale locos, but IMHO Atlas and Kato locos have far BETTER motors. They really crawl at low voltages (DC) and they have flywheels and better electrical pickups.
Look into quite recent Fleischmann steam locos for example. They have one flywheel (if you are lucky), most of them still have light bulbs, and they don't crawl at low voltages. Luckily, Brawa is now putting LEDs in N-scale locos.
Again, this is just my personal opinion. YMMV.
Javier
