Original Garcia's is decent, I think if my wife wasn't an A-list hispanic cook, I would probably rate it higher if comparing to a Chevy's or whatever, but it's average. You don't see a lot of high-difficulty stuff on the menu, and it's pretty much a different combination of beans, rice, tortilla and your choice of meat.
I did try the taco salad one afternoon and it was fairly decent.
If in this part of Phoenix though, it's really the only option - not much to pick from around there.