model power flextrack-
I've used the stuff, over 10 years ago. I remember they make brass and nickel silver. The brass has that obvious "yellow" brass color. The nickel silver is duller than the bright and shiny atlas track, kinda the color of stainless steel. It wasn't steel, though, because I could solder to it.
I really can't comment much on the quality of the track itself because it was so long ago. The layout I had as a kid had a mixture of many track brands, and as far as I can remember the model power ran as good as the atlas and got dirty about the same. If I was still using code 100 HO, I would consider model power track vs atlas and probably choose based upon appearance of the ties, or if I could get the model power significantly cheaper. If you are building a module, it is best to stick to the standards of the club for the mainlnes. In fact, on a small module or layout, the cost difference for just a few pieces of track is negligable.
kevin