There were a lot of the Lippert aluminum 4-steps at the RV show. I tried a few of them and not quite sure what the advantage was for going to aluminum. If anything I think they flexed more. Of course at an RV show they get a lifetime of use in one weekend.
I'm thinking they would be lighter and maybe a little easier on the hands, opening and closing.
"Lighter" - Strike that, I'll stick with easier on the hands, opening and closing.