Russell,
I've worked with AL busses before and I think that they should be got rid of, the world over!.
Give me brass or Cu, any day, something that has a certain level of mechanical integrity.
The thing that I hate the most about Al, is the fact that, ALL the Busses, have to be that much bigger and heavier, as compared to Cu.
And the corrosion problems....don't get me started now, I work with Al, quite frequently!.