There's one reason to go to Burrito Boyz - the food. Hands down the best burrito I've ever had, and they are consistently great with their food, especially given the price.
However, the Adelaide St location is always slow - often taking 30 mins from walking in to receiving my take out order. I'm by no means an expert, but there are some very obvious inefficiencies and bottle-necks in their process.
I've also noticed that there is a fair amount of cross-contamination of food on the front line (corn in the salsa, beans in the guac, etc.). I'm sure this is as a result of how busy they are, but is definitely something to consider if you have allergies.
But let's face it, a good burrito is hard to find, and this is it.