I live by my walking foot. It will feed the fabric evenly. If you run into a bulky seem the walking will move over it nicely. I'm not a fan of invisible thread. It feels like what I think it is...fishing wire. I do use Superior poly nylon and like it. That being said, when I have the option I never use invisible. In SID you can match the thread pretty close and it won't show. Good luck. I would give both a try on a scrap piece and judge the difference.