Smashburger isn't bad. It's definitely quality for a fast food chain. But much like 5 Guys, Fatburger, and any of the other nondrive-thru burger joints, Smashburger just doesn't justify it's higher price tag (although this one isn't excessively expensive).
I had the 1/3 pound classic Smashburger and sweet potato smashfries. The burger patty itself was pretty good, not greasy at all. The egg bun is awesome. The special sauce is lame. I'm very sadden to say that Smashburger is the only place that's ever served me bad sweet potato fries. The portion is pretty small, the fries didn't stay warm for very long, and putting rosemary (an herb I generally enjoy) on them was awful.
The place is clean and the employees are very friendly. I think Smashburger puts a little too much effort into trying to look like its something better than it really is. I agree with the reviewer who said "good food costs." However, I paid a little more than $7.00 for a burger and fries. Not bad, but there's so many options in the ASU/Mill Avenue area (where for just a few more dollars I can have better food), that I think I'm going to have to pass on Smashburger next time.