So, is polyurethane polyurethane regardless of the manufacturer, or are their important differences between the various brands? I realize that this can cover a lot of different products, including varnish, shellac, and poly-acrylic, so it this is just about products labeled as polyurethane.
Also if there is a difference, is one product better than others for use on furniture, to be used in a home, and subject to normal wear and tear from usage?