Just went to St John from 12/27 - 1/3. We did one night at Lovango on their public mooring balls, only three total public balls are available. There are also five mooring balls for reservation only, I recommend making reservations as soon as you can since it is limited. We actually liked the public mooring balls better because they’re closer to shore and less susceptible to wind and waves from what we could tell.
We did dinner at the restaurant and it was really good. Try the sea urchin gnocchi, you will love it! The fresh catch of the day was swordfish and it was also very good. The bill was around $150 for two of us, which was an entree and a couple drinks each. It isn’t a cheap dinner but it was our one “big night” for dinner ashore and we enjoyed and felt it was worth it.
I cannot speak to any other amenities ashore, as we only did dinner and saw their boutique shops. I didn’t feel inspired to purchase anything from the shops, but there are some options if you’re in the buying mood. We did not feel it was worth spending extra money on the day pass for pool and beach access, so we simply enjoyed some good snorkeling off the boat.