Realtime and faster speeds. 8-point movement system. All firing is by broadside. All sails controlled together. Scenario editor crashed on first attempt.
All ships have the same best point of sail - according to the docs, and it is dead aft.
I'd say this one is well worth it. The battle I fought was fun. Haven't tried multiple ship stuff yet. And the cons are mostly nits, except the last one - I think changing it might affect the AI, but different rigs should have different points of sail, and most of them will be 6 points or more off the wind, according to the books. Dead aft would allow only one set of sails to work, for the larger rigs, and would be difficult at best for the sloop rigs that did work better.