If the OP is really concerned about aluminum vs fiberglass, rent one of each for a week or so. Then you will know the difference in noise, vibration and all the other quirks people seem to like or dislike.
My only concerns are dents vs. delaminations.
Fancy artwork and sculpted designs vs. traditional styling is of little concern to me.
Remember, the floor plan is everything, it remains when all else is forgotten. The DW usually calls the shots on that one.
Renting gives you a chance to evaluate a TT before you spend the big bucks.