Thanks for giving Suzanne, and the rest of us, your hands on experience. Suzanne stated her machine is sitting down inside her cabinet. That combined with your experience of it being helpful on a placemat size area leads me to believe this is probably a good purchase for her, unless she wants or needs to spring for a new finish on her cabinet, because on a home machine, no matter your set up or quilt size, this is about all of the area you will be able to quilt at one time anyway. You are always limited by the throat space on your machine, so if, as you said, this does help an area of that size, it will be the perfect item to eliminate any drag on the bed area of the machine.
Now, if she or anyone else is looking to refinish their wooden cabinet top, it sounds like you have found the right combo for a slippery surface. :D