Hi T,
I'm just back from Cambrils myself. Didnt know anything about it beforehand but was pleasantly surprised by the place. We rented a house there, so we didnt stay at the camp park. Cambrils has a great big beach, lovely restaurants down on the marina and is good value. Salou and PortAventura are only 10 minutes away. I read somewhere that the PortAventura park is so big that you will need 2 days to get round all of them!
TripAdvisor.com is a great site to find out about these places. Just put Cambrils Park in the tripadvisor search engine and you will see lots of reviews from people who have stayed there. I took a look at most are giving it 4 or 5 out of 5, so looks good!
JT