I went for the weight-savings. A steel trailer the size that I wanted (to go behind a motorhome) is reeeeealy heavy and would be much harder to move by myself.

I think Surf City said he was looking at the aluminum just because steel trailer prices have been climbing over the last few years - I heard the same thing from two dealers in Florida, too. The problem is that some of the aluminum trailers that you can get for the same price can be flimsy and buyers complained that they had to add reinforcement after the purchase. The aluminum trailers that cost a little more than the steel are lighter, durable and worth the narrowed differential (IMO).