I have the Brother CS6000si and it stopped working in less than a year. I got some error message, took it to a Brother repair shop and the technician told me to ditch it and buy another machine. He said it wasn't worth fixing. It is a very lightweight machine and not for heavy sewing.
I use my vintage machines to quilt with and they sew all types of fabric. The vintage machines have metal parts that make them more heavy duty. I have a Singer 15-91 and a 301. I love them both.
Check Craigslist, estate sales and your local thrift shops for a good machine at a reasonable price. Recently on my local Craigslist someone is selling a vintage Kenmore with a host of cams for all sorts of decorative stitches for $145.00. I am thinking about purchasing it. From Craigslist I just purchased a Singer HD 110 heavy duty machine for $30.00. Good luck on your machine hunt.