It's not easy to make an expansion for a mature gaming system. In addition to failing to do so personally, a number of commercially available modules didn't quite make the grade either. This finds a happy medium between capturing the imagination and the feel of airships, while mechanically lightweight and aligned with the Pathfinder rules set. I tried making airships work in Pathfinder before purchasing this, and am impressed with the ingenuity of a few of the mechanics. The heavy-handed solution I came up with is inferior to the solution this product presents.
As far as needing polish, I believe the word "sale" is used in a number of places where "sail" should be used, I fear a few of the buoyancy and propulsion prices may be on the low side, the turning rules need some clarifications, and I have one question about movement (I will ask in a comment, creators seems to be friendly and responsive).
Great work, great price, no regrets about buying it! I look forward to my next campaign!