Mexican restaurants in Pittsburgh (including Steel Cactus) have no business charging people for chips and salsa; it's the only place I've ever been where that happens and it's riddamndiculous (*steps off Soapbox*).
I don't hate Steel Cactus. I would totally go here for happy hour or dinner, mostly because I am a Mexican food fanatic and could eat it pretty much every day (it's a convenient location for me, and sometimes one just needs a taco immediately). If it weren't convenient, it's unlikely I'd go seeking this place out.
The best parts: the rooftop patio, and happy hour drink specials. Kudos for that, Steel Cactus.
The least-good parts: the food is, in general, bland and unexciting. While the price point isn't bad ($10-13 for most entrees), they could use a happy hour food special or two. My personal preference is for more authentic, cheaper Mexican food, like Emiliano's on the South Side.