actually, an aluminum frame would be one of the biggest reasons for me to go back to steel bars. I'd be a lot less concerned with overall weight and steel bars aren't going to flex on you when you're really mashing like aluminum ones will.

i've got alu bars on an alu stem at the moment, and its just flexy enough that i tend to hold back a little in a full blown sprint.

but i mean, this is all assuming that carbon drops aren't magically granted to me for cheap monies.