If this is available for your couples' getaway in Santa Cruz, you need to book it right now. The experience of looking up at a circle of trees through the skylight as you wake up is unforgettable. An enormous amount of care went into building and designing this place, evidenced by the attention to detail and high-quality finishes. Besides that, the treehouse has all the usual amenities including plumbing & wifi.
The cherry on top is that Lindsay is a great host, very responsive and friendly. Other reviewers mention some noise from the road in the morning, which I guess depends on the day because we didn't hear very much at all. But the hosts thoughtfully provided ear plugs & eye masks just in case noise or the sun was an issue. Note that guests must be able to climb stairs for the entrance as well as the bed in the loft area.