I preordered a copy from Amazon when it was first announced and had my copy arrive on the day of release, but I've only just recently had a chance to play it. Alas I wasn't all that impressed.
Lets start with the good points. FS is well presented, mostly well written and illustrated with pictures from various Osprey titles and a selection of GHQ models which aren't so brilliantly made that they demoralise the reader. Plenty of diagrams, counters and play aids to copy and cut out (and these can be downloaded from the Osprey site so no need to get worried about bending the pages back too much). A good selection of fleet lists (Britain, France, Spain, the USA, Russia, Portugal and the Netherlands as well as privateers and pirates). And the rules are very simple and play quickly.
The problem I found is that they don't feel like a set of age of sail rules. The movement rules use dice to determine how far a ship can move which is fine (FLoB) uses dice as well, albeit in a different manner). But under these rules it is quite permissible to turn directly into the wind, move a considerable distance directly upwind and then make a turn to put the ship back on a point of sailing with the wind over the port or starboard side. For example, I had great fun driving a US privateer rolling seven movement dice with a "navigator" trait (this allows some reroll of failed dice) moving in ways that no sailing ship should ever be seen to be doing. A simple house rule removes the problem - turn into the wind and lose all remaining movement points unless they are used to perform a tack - but I can't help thinking that rule should have been there from the start.
As far as manoeuvrability is concerned, all ships are equal. So a nimble schooner rigged privateer turns as quickly as a lumbering 1st rate. Which, combined with the movement and initiative system gives some interesting and atypical possibilities as ships of the line deftly manoeuvre around frigates into the perfect raking position - in one game recently a British 64 did just that, sailing around the Constitution to perform a rake which killed the US ship in a single turn of gunnery). Suggestions? - increase the minimum move between turns for ships with lower manoeuvrability, or place a limit on the total number of turns that can be conducted in a single game turn.
Also on the movement front, any damage causes a ship to take an "anchor" token which slows movement. Further damage affects fighting ability, which is a simple halving of effectiveness - no graceful degradation here but since this is a fleet action set of rules (in theory) thats OK. It is possible to remove damage if a discipline test is passed, but damage tokens come off before the anchor token (the author states "damage control takes precedence over getting moving"). To me this feels completely wrong, going against the evidence one sees in reports from actions. I would prefer to see anchors removed first, at least as an option that the player controlling the damaged ship can take. Ships just seemed to slow down far too easily in this game. Also, as befits a set of fleet action rules, there is no choice of shooting at hull or rigging (much to the annoyance of some friends playing the French - another house rule perhaps that allows players to select rigging over hull, automatically makes the first damage token suffered an anchor and allows a ship to hold 2 tokens).
The initiative system and its interaction with the movement system (initiative winner moves a ship first, then the other player moves one of theirs, players continue to alternate) mean that the initiative is practically always with the larger fleet. Which is critical when also combined with the degree to which ships can manoeuvre.
Ships die very quickly in this game, especially at short range. Awfully fast, in fact many ships in a stand up slugging match were dead in the water after a turn of gunnery and sunk or struck after 2. Which makes for a quick game, but again doesn't really feel right.
To me thats quite a lot of negatives and, whilst the production and supporting material in terms of presentation, fleet lists and scenarios is good the whole package was, for me at least, disappointing. I expect these rules to be similar in their appeal to Warhammer Trafalgar - popular because of who is publishing them and appealing to casual gamers but ultimately disappointing for those with a deeper knowledge of the subject. Which is a pity since I think that, with a bit more effort, they could have been so much better.