I went with it originally since Dave Gentry said it was easy to apply and tough. It's cheap, at $4-$5 a tube and three tubes covered my kayak with half a tube to spare. As a newbie, I wanted something cheap & tough. Having to paint over it for UV resistance isn't a big deal, for me.

I will try simple varnish over polyester on a future boat. For my first, I wanted something tough.