not for sure what is the best, but i would be careful,trex is ground up milk jugs and pallets and it is then extruded,if you look close you can see the nails or staples(small pieces) from the skids, it is right at the surface but smooth ,but with that the steel pieces can rust faster with the salt causing rust staining.i have installed a few decks with that stuff in the ninetys ,real soft when it came to screwing it down or sawing.could' nt use nails,so the screws should be coated.hope this helps.