I'm not particularly a fan of Kayak Deck bags. I find that they then to make the kayakig experience feel cluttered. They also make it more difficult to roll the kayak, and I don't get a good view of the compass.
I don't like that the deck bag is two layered. The outer shell is not waterproof, and instead there is an inner bag for things that can't get wet. Apparently most deck bags are like that.
On the positive side, if you don't have a small cockpit hatch, these bags can be useful for things you need quick access like your phone, GPS, and some power bars.
This bag does what it promises so if deck bags are a personal preference of yours, then this bag will definitely work. It is a little pricey thought...