The treehouse cabin in Watsonville was amazing and magical. The cabin is small but the layout is inspired and my daughter and I never felt claustrophobic.
The hot tub seemed a ho-hum amenity at the time we booked but we used it a lot over two and a half days and really enjoyed it. It is connected to the cabin by a lovely deck.
The distance from parking to the cabin was somewhat long and the pathway narrow. We loved that except for unloading and re-packing the car. It took the two of us two trips in each direction, which we didn't mind, but prospective guests might want a heads up.
I recommend timing a walk from parking to the cabin in the early evening. Lots of the usual fauna (banana slugs, etc.) but the big fluffy chickens are sure to make you smile.