Disgusting!! I left with a stomach ache and empty wallet. My boyfriend really wanted to try out Smashburger so I agreed. Boy I wish I would have stuck to my guns and said NO! Boyfriend had the mushroom swiss and said it tasted not so great. I had the Arizonian and the only thing on it that I enjoyed was the guacamole. It was the most awful tasting burger I have ever had. Unless of course you love the taste of grease because that's all the burger tasted like to me. I think their whole gimmick is to "smash" the flavor out of the meat and sop up all the grease flavor.
I tried the Smashfries too and meh. They tasted like frozen shoestring fries thrown in the over. They were not appetizing.
Definitely not a fan and will likely never go back.