Speaking of ore trains, we (PIHR) ran a 137 car ore train (+ caboose) at our work session last week (shortened it to 110 for the weekend running). This train is a mix of manufacturers with a large number being Atlas. A number of the cars at the very front are diecast. You can see the ride height difference when you get to the close-up run-bys when the silver UP cars show up on screen - they are all Atlas. When running, they are not that noticeable to people who aren't looking for that sort of thing. I agree that the Atlas/K-Line/RMT cars are the best, and the Atlas cars can often be had at train shows for very low prices.
Andy