I have mostly Aristo track, evenly divided between brass, stainless and aluminum, purchased in that order. I started with brass, but had to clean it frequently, so added some stainless, which worked quite well. The little bit of corrosion that occurs on stainless is the most conductive of all the corrosion.
Then I made the switch to battery-R/C about the time that Aristo came our with their code 332 aluminum. Since track cleanliness was no longer an issue, the aluminum track worked well for me. This year, I noticed that one length of Aristo aluminum track had become twisted, becoming out of gauge, something that others in our club have noticed, as well. So far, only one length has been affected, though. Time will tell.
Some have a problem with Code 332 (332/1000 inch high) because it is way over scale, and recommend the use of Code 215 or Code 205, instead. I'm not that fussy about scale, and prefer the strength of Code 332. The other, smaller sizes seem kind of flimsy, to me, for my use. I've seen it well used on layouts that are built on a secure base, like benchwork, or even concrete roadbed. You mileage may vary.