I used to walk past this place every day on my way to work and I never thought all that much about it, until a friend of mine, who loves Mexican food, decided to have his birthday lunch here. It was then that I discovered that I didn't mind Mexican food all that much. It's pretty cheap, and the burritto was pretty good. Actually it is one of those places where you get to pick and choose what you put onto your buritto, sort of like a Mexican subway (though unlike Subway you won't find them on every corner). They also have, not surprisingly, beer available, but then again I have come to expect beer at a Mexican restaurant (and they also tend to be Mexican beers, which means you can have a Corona with your burrito). Okay, it may look like a bit of a fast food joint, but it's still pretty cool.
If your looking for cheap and "nasty" Mexican this is your place. Not to say that the food is bad or anything. It's just doesn't have that feel like the place is "clean." I will say that the prices here were more than reasonable and my burrito was a decent size and tasty.
Truelocals who want to spend a little more will go 15m down the road, to get what was fresher and cleaner Mexican. But I don't want to take away anything from Burp, if you are looking for a quick Mexican feed in Adelaide City and your on a budget, head to Burp.