Unbiased view as a player with no experience in Black Flag.
The game has stunning visuals, easy handling on ships, much to explore, ranks to rise through, things to unlock and upgrade, has half the MMO grind of your standard years-long character based MMO's. Is captivating and offers loads of fun for a pirate loving explorer who enjoys a decent storyline. The game has potential for growth in customizations, extended content and in-depth ship battles/missions.
The game in it's current state does offer hours upon hours of enjoyable gameplay in a free-to-explore open sea. Ships do vary in size and style which are designed for playstyles such as ramming, fire, explosion, etc. with various types of weapons that are interchangeable to your own design including ethereal weapons to fight ghost ships. There is one main social hub (Sainte Anne) with option to stop on your adventures at various camps/outposts to store your items and save your progress.
You can follow the storyline, rise through the ranks, build glorious battle ships, buy/sell/trade, job boards, bounty boards, crafting stations, do side missions for coin and rewards, plunder other ships and sites on the map, farm materials from your ship, plunder ship wrecks, pick up free booty from the sea left behind by other players and NPCs, run a hidden business for extra coin, join server events, wreak havoc on various NPC clans and camps, take down other notorious pirates and their fleets, just run amuck and become the infamous pirate you always wanted to be. Don't forget to upgrade your spyglass and get the jump on your sworn enemies! Need you more?
I cannot wait to see where this game leads as it develops. It truly offers so much already as its own entity with its own identity. I find it is worth the price for what it offers in the current state.