I think Mad Mex's food is a bit overrated, but the magaritas on happy hour special are a good deal, and tasty. The beer menu is awesome! Expensive, but excellent selection. The Shadyside location is spacious and comfortable.
I love their black bean dip (and, accordingly, the black bean and pineapple quesadilla). Much of the other food I've had here is pretty Meh and definitely "Mexican inspired" rather than close to anything authentic (or even authentically Tex-Mex-y). The chips and salsa make me downright hostile because a) they are expensive, b) the texture is too thick and they taste as they came directly out of a supermarket-bought Tostitos bag, and c) they are often somewhat stale, so it's more like that Tostitos bag was bought and left open 2 weeks ago. Gross.
The Gobblerito is, indeed, a thing of Seasonal Beauty. If you don't mind the resulting carb-coma, it is definitely something to try.