Have had 3 or 4 of each. I prefer alum because its lighter and offers me more payload in my TV.
I have not found much difference in the cleaning and waxing of it with the products I use. It does take a little more time to re-caulk it due to the corrugated aluminum.
The aluminum can be repaired by any handy person using basic tools. Smooth sides will take more time, expense and a more experienced mechanic. A few dealers will tackle it many have to go back to the mfg.
If you plan to live in this for some time and you have a leak causing delamination, would you rather hire someone local to repair it on site and be done in a day or ship your trailer back to the mfg ? I have had an RV at a mfg for many months at a time loosing its use. It's your home and time.