I've worked with some of that "vinyl" wood products. Granted it was for interior finish work I helped a friend with a few years back. It sort of weird to work with. It took awhile to get the speed I went through a cut with my miter saw. The stuff sort of melted as the blade went through. I finally got it speed right so there was the minimal ball of melted product on the back side to clean up with a razor knife and sanding. He got the stuff cos' he got it cheap. If I had my choice I wouldn't use it. It gummed up and dulled two 12 in miter saw blades. My bud was very cool about it, not only did he take the blades and get them sharpened, he bought a new blade to go with the deal. Those blades are not cheap.
The other draw back about using composites, vinyls, ect... you may not be able to paint them, so the color you get is what you live with, regardless if you change the color of your home.