I've been to la Roca a few times, and each time I ended up questioning why I went. But three times is the limit for me as far as second chances goes.
For those times when I did allow for forgiveness, I always believed the previous visit must have been a fluke; Maybe the waiter had a bad day, or maybe I had been unlucky and gotten their one bad waiter. The food was good enough to give it another try, but not again.
As others have mentioned, the food is very good, but overpriced, in my opinion. I also agree that the waiters are professional, but I discovered there is an underlying disregard for the customer (contempt might be a better word).
It appeared to me that attitude was almost institutionalized, like the waiters had an understanding and exhibited a collective disdain for gringo customers. At least that was my take.
All three times I've been there I had company. Each time there was a mix of Dominicans and gringos. What I saw was a complete deference toward the Dominicnas and a bias toward the gringos, so much so that it was noticeable, awkward, and uncomfortable.
In each of those visits, the waiters made obvious attempts to lead the ladies into ordering the most expensive meals on the menu, almost to the point of insulting the gringos, who would obviously be paying. By the way, the waiters in each case had a little entertainment trick to show the girls, much like an animation team would. Interesting.
It had the feel of a scam to me, and while no one said anything to the waiter, I noticed the men all ordered the lower priced items, and the women, well you guessed it, the most expensive dishes; Four people with a bill of over $250 US the last time, and that was indeed my last time.