Just got home from a week at Sea Spirit, and I can confirm that it is a very pretty little villa that delivers everything promised in terms of privacy, view and the sounds of waves lapping at the cliff below your front deck. Some of the design elements are a little awkward and there's a shortage of closet space, but it's a lovely place for nature lovers and a good deal at the price.
The house was built in 1993 and has been kept up nicely. The hot tub works well, the grill works, the fridge keeps things nice and cold, and the blender crushes all the ice you can shovel into it. We thought the bed was exceptionally comfortable - a firm mattress with a thick foam pad on top - and there are lots of pillows. The ceiling fan does a surprisingly good job keeping the main room comfortable, even at the hottest time of year. AC in the bedroom is a little loud, but cools the room down fairly quickly.
There are plenty of outlets for plugging in chargers and the wireless internet connection was solid as a rock. However, other electronica is pretty basic - a TV that gets only one channel, a DVD player (which we never used), and just a boom box for music. There are no CDs except a handful left behind by other guests, so bring your own island music. And DVDs if you want to watch the TV. There's a good stash of nature and local guide books and a shelf of random books.
You'll probably spend more time on the deck than anywhere else. Be sure to buy some powdered sugar for the banaquit feeder and you will be endlessly entertained. The covered deck is great mornings and evenings, but there is very little shade in the afternoon - good time for a siesta in the air-conditioned bedroom. Or sunbathing, if you like that kind of thing.
Additional features that we didn't use: Washer/dryer. Cute little sleeping loft with 2 twin beds. Picturesque gazebo: close to the house but requires putting on shoes to descend a steep, rocky path. We went down there exactly once and took pictures, then forgot all about it.
If you are not familiar with St. John, be aware that this villa is off on the far corner of the island, as far away from Cruz Bay as it is possible to get. A rental jeep is a necessity. It's probably not the best choice for first time visitors or folks who like the beach bar scene. But it's perfect for a couple or small family that wants to commune with nature and explore some of the "off the beaten track" beaches and hiking trails on the quiet side of the island.