We booked a portrait session last summer. The photographer did a fabulous job. We did it early evening, before the sunset cost kicked in, mostly b/c I wanted true daylight. We chose to do it on the beach, and it actually ended up being a great mix of background colors. Some photos have the water/rocks, some mostly beach/rocks, some beach/greenery. We went to the far left side of the cove, so all of that will make more sense if you've been there. She took some "action" shots, with the kids walking or running toward her. We had some great shots where the kids are just shaded dark with light and ocean behind them. She went to a lot of effort to take a mix of kids-only, DH and me only, me w/kids, DH w/kids, and 4 of us, lots of various poses. The cost gets you all the shots, no actual prints though (which was fine with me, so I could take my time at home picking which shots to print and what size).
Book in advance, over the phone. I believe I booked in May for a June date, but it seemed like the "open" dates for booking varied somewhat. I had to shift around some spa and salon appointments that were already booked, in order to accommodate it, so it didn't open for booking as soon as those or Aunty's pre-registration.