On the mainland you get more produce and a wider variety of food. I was on Cayo CoCo and I think there was only 1 or 2 flights per week so everything would come in by plane or boat. The few times we went, there was some sort of Chef rotation/kitchen training [They sent their Corportate Executive Chef from HQ Italy] going on and the food was really good. They have theme nights every night and had a schedule posted in front of the dining room. There's always a pig roast. I think the desserts were just okay.

The quality and type of food you get also depends on the resort you stay at and their target customer. I found that the Melia & the Sol resorts have decent standards and are usually right on the beach.

Each resort also offers a full range of schduled activities, volley ball, water polo, pool hockey, poolside aerobics etc.

On Cayo Coco there isn't much to do outside of the resorts.