This set of rules is quite comprehensive and can cover a wide range of ancient nautical battles. I have not played the game yet, but the rules are reasonably well set out and written in plain english so I feel confident that when I do play I will understand what is needed.
The card-based turn sequence seems like a great game mechanic, simulating the relatively unpredictable command and control of the period. Giving each admiral a limited number of Tactical Initiative Cards restores some active control to each player, but also forces the players to think carefully about when to take the additional movement turns. The basic game mechanics for movement and various forms of combat seem relatively straightforward and should play quickly. One feature the rules lack, which I would appreciate, is a comprehensive QRS that places all of the combat tables on a single page - as it stands they are spread through several sections and I can see myself flipping through searching for the right ones during a game (although the table of contents is detailed enough that finding them should be reasonably quick as is....).
Other strengths of the rules include fleet lists for particular navies, with short descriptions of the state of naval warfare in the periods, as well as short descriptions of the ship types and their distinguishing features. I learned quite a lot reading that section. The rules also contain a set of campaign rules and maps for Mediterranean operations. The campaign rules seem simple enough to actually play, yet have enough period detail that they would be interesting and would enourage players to consider how to use supply and scouting assets, as well as main-line battle formations. The rules for generating terrain for tactical battles is also a nice touch.
Overall, I haven't found anything glaring that makes me unhappy, and there are many excellent features in these rules that could be used as-is, or easily adapted for use with other rule sets.
I believe Salamis ad Actium gives excellent value.