Here are some relatively recent discussions we have had that might give you more information, but, as the previous posters said, it really is a good idea to "eyeball" the machines and give them a test with the things you are now having problems with. What works for one might necessarily work for someone else. Good luck and let us know what you decide.
http://www.quiltingboard.com/main-f1...s-t272153.html
http://www.quiltingboard.com/main-f1...a-t271602.html
http://www.quiltingboard.com/main-f1...e-t269676.html
http://www.quiltingboard.com/main-f1...e-t271152.html