Being fluent in Vietnamese, I haven't experienced some of the problems other reviewers have, but nevertheless, my rating still seems to be consistent.
I really enjoy the Banh Mi here as they are fresh, and have perfect ratios in terms of the bulk of the Banh Mi itself. Where I deducted one star is due to the inconsistency of their mayo in which I have found to sometimes be a little sour/stronger. Not that big of a deal, but sometimes throws me off a bit. I usually just buy the Assorted Meat (Bánh Mì Thap Cam) but I have discovered a new favourite. I highly recommend the Bánh Mì Patê Bo Chà Bông which translates to Rousong and Pâté according to Wikipedia. It is less filling than the assorted meat, but I've found it to be tastier and less heavy. Also, you can ask for it to be spicy where they add grounded fresh peppers. This will cause some parts of the Banh Mi to be spicier than others so eat with caution!
Anyways, I think this is a great place to grab some delicious Banh Mi, but beware that you will have to face a great language barrier, and perhaps some small inconsistencies.