Chrome does take a beating, but its alot easier to clean than polished aluminum. With chrome, all you need is steel wool, then if you want to make it more shiney, you can put some chrome polish on it.
With polished aluminum, it gets corroded and even rain puts spots on it. Its a pain in the *** to clean, and you can pretty much never make it look "new" again like you can with chrome.
If i had the $$ i'd defenitly get chrome.