My wife and I went here a few times and had good experiences. So when my family was looking for a place to get together over the holidays I recommended BJ's. This was a big mistake.
Our reservation was for 6:30 but the table was not ready until well after 7. No problem, a few members of our party were late anyway so no harm no foul. We had 16 people and it was busy that night so a few small errors in service would not have been a big deal. Though, almost everyone had complaints. Twice I ordered one of their beers only to have a server try to give me a mixed drink. My cousin asked for a dish (cant remember) and was told they were sold out only to see the same order leave the kitchen numerous times afterwards. One of our family members received the wrong dish, multiple items were forgotten and when the check came the servers proved completely incompetent in dividing the check between 3 groups. While my sister tried to assist them in separating the bill one of the mangers stood there and did nothing to assist his struggling employees.
On our way out my sister approached two of the "managers" only to have one turn face and walk away from her and the other (younger guy) offered no explanation, no resolution, no nothing. When she inquired further he at least offered to take her information and have someone follow up with an apology and possible gift card for our troubles ($500 bill by the way). One month later we have heard nothing.
The food here is excellent and I may be back in small groups, but large groups should avoid BJ's like the plague.