THey did a good job of labeling the map with icons so you can find everything right way. They thought out what happens if creature were unware. There was enough touches of detail (that extra something) that my players will remember it and keep refering to it. The only thing is the harpery's luring song reaches a huge distance since it auditor. It can easily effect the Kenku in the adjacent area if not the whole map. Since it based on hearing and the harpy couldn't see the party or the kenku until they reached her it caused a lot of confusion (good confusion), but that was never addressed. They explained how both enemies viewed the other which made resolving the situation easy.

I would recommend the adventure.