I don't think there is such a thing as a longarm that never has tension issues, because those can and do happen just because you are moving the machine while it is stitching. A longarm is a huge sewing machine, and all sewing machines are designed to be stationary while making a perfect stitch. When we start moving it in all different directions, with fluctuating speeds, here and there it becomes hard to make the perfect stitch, and fails. I think most longarms do a great job of making good stitches under such adverse conditions. Right now your problems are extreme, though, so you obviously have other issues besides movement contributing to the problem. Keep us updated on what happens after your dealer gets done with it, and good luck.