Thanks Perry,
I don't think either one has an advantage over the other one. I had two solid weeks building two of these out of wood and afterwards I said never again. Life is too short. The aluminum ones are a $$$ bargain compared to the time I have in these two wooden ones. I laminated several layers of 1/4" bathroom floor underlayment plywood for the two long plates, which uses water proof glue and fiber, so these should hold up for a long time.
The front end is machined of Phenolite which I salvaged from the dumpster of a large tool and die shop. That stuff is hard, heavy, durable and expensive. I wanted to use another material other than wood but hind sight tells me the laminated wood underlayment would have worked equally. The front end isn't as easy to adjust vertically as a rest with a threaded post and mariner wheel but since mine is dedicated to one gun quick adjustment isn't an issue.
If I would have had a heavy knee mill, capable of machining aluminum, I probably would have gone down that road. But since I don't then wood was my only option given the tools that I do have.