I have two low end machines. A Brother XR1355 from Costco and a Singer Confidence Quilter 7469 from Joann's. I do all my FMQ on my Singer and piece etc on the Brother. Have had no problems and quilt king size quilts on the Singer.
Wanted a few more features that the Brother had such as variable speed and more decorative stitches. Can't afford the expensive models either, but love both of these machines.