We camped at Pirateland for a little over a week a couple of years ago and had a great time. It was very hot/humid though, so make sure your AC is in good shape, or be sure to hit the pool/beach in the afternoon to cool off. The bathrooms/comfort stations were just o.k. It's tough to compete with Fort Wilderness for well maintained restroom/shower facilities.
We're returning to Myrtle Beach this year, but staying next door at the Myrtle Beach State Park. Besides being cheaper, we were just in for a change and wanted to try something different.
I'm sure you'll have a good time!