I have used the Kiwi Grip. It will work very well in your application. We used it on one of the offshore racing sailboats I'm involved with and it has held up very well. It has been on for two seasons now and we will probably recoat next year. This boat gets thousands of miles per year put on it and sees severe abuse. I would imagine that on the deck of a pontoon boat you would probably get a decade out of the stuff before having to recoat. Recoating requires only a clean and dry surface. No sanding or other prep.
Application is easiest with two people and you do need to follow the directions. The product is sensitive to temp and humidity during application.
We applied ours in direct sun which dramatically shortened the working time of the product. This can cause it to clump if you are not careful. Overall it is very easy to apply. I would say it is easier than using a sand based non-skid. If you can paint a wall in your house, you can apply this stuff like a pro.
I've attached a pic. The gray product being applied is the Kiwi Grip. I'll have to look to see if I have a more detailed photo of the texture.
