As far as Mississauga is from Mexico (though they both start with a "M"), this place is definitely one of the better places for Mexican food in the area, dare I say all of Toronto?
All their tortillas and ingredients are fresh, the guac is great, generous portions, chip and salsa, fried tortillas drizzled with chocolate and cinnamon for dessert, and some authentic mexican flair... this little diner spot definitely beats the Mucho Burrito and Chipotle chains in Toronto.
I usually get the wet burrito, which is about $11. It's heavy, filling and might put you to sleep, but it's oh-so-good.
For a slightly healthier alternative, the also have a salad bowl which I've also tried which comes in a (i think) made on premises crunchy tortillas bowl. It's pretty good, but I'd stick with the burritos, enchildas, tacos, etc. etc., which are all great.
Being a fan of tex-mex, you can't really compare it to places in the US of A which has aweeeeesome tex-mex for dirt cheap... but for Toronto, this place is just awesome and satisfies the tex-mex cravings I get every so often.