We ended up at Coledale Camping Reserve just south of Sydney on the weekend. Great little spot and one of the rare places you can set your tent up with an actual view of the waves. On Saturday we had a terrific lightning storm out to sea and good rain. We were able to sit under our awning and watch the light show.
Pros - on patrolled beach, close to Sydney, plenty of grass, good amenities
Cons - can be crowded (go in bad weather - that thins them out), not that many sites, street lighting, only the northern sites have beach views, it's not really away from it all
Well worth a look if you just want to get away for an overnighter. Probably less crowded during the week.