Having had both Fat Bastard and Burrito Boyz (They're across the street from each other- don't mix them up!), I gotta say- Burrito Boyz comes out on top.
However, there's been a few things at this location that are less than stellar. The staff can be hit or miss - some of them (at least the front counter staff I've dealt with) seem to be fed up with customers. The difference between way they will talk to customers and then turn around and talk to other staff is astonishing. You'd think we were personally insulting some of them.
Additionally- and it's not Burrito Boyz fault AT ALL- parking is usually difficult at this location. Because it's so popular, the small lot is almost ALWAYS full, and you'll have to drive a few hundred meters down a side street to park if the lot is full.
If you want a hot, tasty burrito and don't mind brusque staff and a bit of wait (The meat is cooked FRESH!)- this place cannot be beat.