We went to Cambrils at Easter and the pool was cold, The kids played in it, but not for hours on end, Would be warmer by the end of May though. Mind you, heated pools are not normal in campsites, in my experience, maybe in Normandy where the weather is cooler, but you cant really expect one. Wetsuits would be a good idea.
The restaurants on site are very good and the supermarket is the best I have experienced on a camp site.
We went for 6 days and hired a car and hardly used it. In our case, taxis would have been cheaper.
It was a great place to visit and I would definitely go back.