I am looking for a 15 inch planer and after some reading I am interested in the grizzly 1021x2 and the 0453z. The x is built in a Taiwanese IOS 9001 factory and the z is built in China. Looks like the x has a byrd cuter head and the z has a grizzly cuter head. The z has a built in mobil base. The x is $100 more. I would like more imformation and advice. thank you Allan