My family (husband, 20 year old daughter and 23 year old son) took 5 days to relax on the cape. Green Harbor was a perfect place. We were all able to fit in one unit because it had a queen size Murphy bed, a double and a single bed, in addition, it had a full kitchen so we were able to sleep in and eat breakfast (and lunch) together.
The resort has a lovely pool and a small but beautiful beach. We opted for the beach because there were lots of little kids at the pool and my "kids" are grown up. There was a creek just behind our unit that leads to the bay and then to Nantucket sound so the water was calm and lovely. We were able to take our Kayaks for an easy paddle around the creek and look at some lovely homes and scenery.
My only complaint is that I wish I had known about this place when my kids were little.
If I were to improve the place at all, I would place either ceiling fans in both rooms of the unit or add an air conditioning unit in the bedroom of our unit. It got a little warm in there if you closed the door at night.
The cabin we were in was cleaner than any hotel room I've ever stayed in. The staff couldn't have been more helpful. Our room was cleaned daily, trash removed, beds made, etc.