I have to say I was pretty disappointed with Big Fat Burrito.
I'll agree that the service was friendly and quick enough, but the burrito itself wasn't much to get excited about. Contents were OK I suppose, but the salsa had a strange ketchupy/BBQ flavour that didn't go with anything else and it put the rest of the burrito off. None of the flavours seemed to mix together, and the chicken was a little dry too.
This was the first time I remember getting a "small" and thinking that it was actually small, too. If it was tasty, I would have been sad that I didn't get large.
I didn't try the yam option, because I usually try a new place with a standard chicken burrito to even the playing field. this might be a good one for vegetarians, but I'd recommend skipping the salsa.
I've heard that they make a good breakfast burrito, which I might try, but I won't be back for lunch when there are so many better, and bigger, burritos in the city.