I never bothered to eat at Rockhouse, always ate at Pushcart. Pushcart used to be great. It is still very good. The table waitstaff has been my biggest complaint in recent years. The food is pretty consistently good to great. Never disappointed in the food quality.
I see a lot of people promoting Ivan's. Ivan's is very good to excellent, no doubt. Don't overlook Kuyaba on the beach. Just as good food, somewhat lower prices, and I find the beach tower table the most romantic dining spot in Negril, you just have to get a waiter/waitress who doesn't mind stairs! But....that's just moi! Both great restaurants.