While I am not a regular here, I do frequently visit this establishment. Zoo Sushi features some of the tastiest sushi I've had, and the sushi chefs are pleasant and entertaining. The quality of the food remains consistently good. Very high marks in this regard.
Unfortunately the exact opposite is true for the floor wait staff. On the vast majority of our visits, the wait staff seem to forget the patrons sitting at the sushi bar (and it's not much better on the main floor). They seem to be much more interested in talking amongst themselves, visiting the kitchen, or hanging out at the drink fountain rather than doing their primary job - taking care of the customers. On virtually every visit while sitting at the bar, the staff has forgotten something for our meal - be it the miso soup (several times) the salad (several times), sushi plates (often), drink service (frequently) and they've even forgotten to bring us a menu!
While we will probably continue to visit - because the food really is good - I would be very surprised to see this restaurant survive if changes to staff attitude and service are not immediately made. Were service to improve, my 'star rating' would be considerably higher.
In the meantime, we will continue to show appropriate compensation in our tips for the service provided (or rather, the lack thereof).
Pros: Quality of Food
Cons: Quality of floor wait staff