I'd like to preface this by saying that I am a former employee of McCormick's. That might make this review more or less valuable to you, but that's your choice.
Believe it or not, the food is actually good. The chefs are really talented and do good work (and believe it or not, I was not a chef). The problem is that the service is so bad that it either arrives cold or burnt to a crisp.
Why does such good food end up so bad? In my time there I have seen employees fall asleep in a back room, I have seen servers leave their tables to go have a cigarette, I have seen servers pick food off the ground and put it back on the plate, I have seen servers take sips of people's beers, I have seen servers get into a fight - a fist fight - in front of customers, and I have seen employees shoot heroine in the bathroom. It's obvious that the work environment is beyond out of control.
Aside from the chaotic employee situation, there is a general lack of respect shown both to other employees and to customers. There has been, and will always be, a vermin problem at McCormick's. Every night you can catch the critters running back and forth across the first floor dining room. If a customer happens to spot one, they are rewarded with a seat change and a free dessert. Otherwise, nothing else is done. Nothing.
The host staff is charged with cleaning the bathrooms. They get to this about once a night, maybe. The general cleaning theory is to slosh a bucket of extremely potent cleaning solution around the floor at night, which produces a smell that penetrates the nearby dining rooms. The downstairs dining room especially smells like cleaning solution and restaurant grime. Customers often complain about the less than sanitary conditions. Again, no changes are made.
There are plenty of seafood places in Boston and I would recommend that you put McCormick's last on your list. If I could give it zero stars, I would.