I'm partial to BB. I have been going there since the '70s, so we go way back
That said, I will admit that it has gone downhill as far as food quality & price hikes since what I'm guessing would be the introduction of the Fantasmic packages. I'm not sure those 2 things are related but they seem to be to me. But anyway, I always shared the surf and turf (filet and lobster tail) with one of my daughters for dinner or Monte Cristo (shared between 4 of us!) for lunch. MC at BB used to come with salad and sides and was much bigger. Portions now are a lot smaller but the prices are not. I don't think the quality is the same now, but as far as I know, the MCs they serve at CO are exactly the same, quality wise. They use the same kitchen, or at least they always used to. The last time I had the surf and turf at BB, while the filet was excellent, the lobster tail was so bad it was inedible, so that's very disappointing and I doubt I would order it again.
I have never had great service at CO. It takes forever, the staff seems harried and therefore not very friendly, and at least part of my order is either wrong, missing, or our food all arrives at different times. Having a reservation has not meant we are seated quickly. The food is no better IMO than BB and it's not cheap, either. I'd rather have the waterside table in BB. Now, BB service has almost always been very good for me, with the exception that you can often feel rushed. However, I prefer that to waiting forever for the staff to bring your food, refill a drink, bring the bill, and then bring back the change.