Another thing to think about is the solvents. Duratex is water based. Line-X and similar products are based on VOCs. I have used both, and without a serious respirator or even supplied air, Line-X is a bad idea. Duratex smells like latex, which is probably what it is. I have Duratex on a PA rack I built. It was built with plywood left over from a project. The plywood was finished on one side and unfinished on the other. When I built the box, the pieces were routed and then epoxied together to make a strong joint, but I made no effort to hide the end grain of the plywood. Duratex made all of that disappear, since I rolled it on with a fairly heavy stipple. It stuck well to both the unfinished plywood and the finished, sealed plywood. That was couple years ago. It is holding up very well. The Line-X type stuff I used was called Rhino Liner. It worked as well, but was more abraisive. It was on the floor of my van. It stuck to that, so I have no doubt it would stick to plywood. My opinion is that unless you want a color other than white or black, there's not much reason to use anything except Duratex.