At the risk of some thread drift (sorry) but responding to Jason: I have been experimenting with coreless motors and coreless gearhead motors with some success. I have lowered the overall power consumption of my layout by over 75%. Hey, I'm trying to do my bit for the environment! 
Jay Criswell at Right-O'-Way has developed some new drives with coreless gearhead motors which I have found to work very well. These are the "lower-duty" versions which work for my modern-era short-line, but he also offers heavy-duty versions for large layouts/trains.
Central motors for narrow hoods
Tower-mounted motors for cowl units:
I have also used Maxon coreless motors from The MotorMan (Microlocomotion) to replace Pittman motors in Weaver and Overland locos with some success.
Recently I've been eperimenting with Maxon coreless gearhead motors in C&LS RS11s. Robin Talukdar 3D printed motor-to-tower adapters for me and so far so good. The pulling power is about the same and the stall current is under 0.5A.
I am now able to use "HO-sized" Loksound decoders in all of them which offsets the cost of the motor upgrades a bit at least. 
