The only gripe I have is that it can be hard to find for someone who is eating there for the first time. I've lived in Ahwatukee all my life so this is not a problem for me.
The Original Burrito Co. is a great little mexican restaurant located in an otherwise forgettable strip mall (A liquor store and Gold's Gym being the anchors). The food is priced well and you can easily feed two for under ten dollars. The burritos themselves are generous in size and tasty, to boot. I really like their green chile and carne asada offerings.
The inside is very small, looking more like a take-out place than a real restaurant. You can sit outside, however, and I would recommend this is the weather permits.
There is no other place in the area I'd rather get a quick mexican meal, for sure.