The Mrs and I tried the open beta for a few hours, but decided it is not for us. There's no real story as such, just picking up contracts from NPCs. As mentioned above, boarding consists of a brief cutscene rather than hand-to-hand combat. It seems you can only disembark from your ship in safe areas, so no exploring small islands etc on foot. Even plundering a settlement was carried out purely from the ship. Ship movement and combat was far less satisfying than in Black Flag or AC Odeyssey IMO.
Appreciate it's an open beta, but the release is only a week or so away and there are real problems with the sound. Your characters footsteps only come out of one channel, and the volume mix is all over the place. It runs smoothly though and the water and weather effects look great.
Glad we had a chance to at least try it out.