I am one who believes in having my machines serviced regularly--if not every year, every couple of years. When you are used to using a machine, if it starts sounding or stitching a little differently or noisier gradually, you don't really notice it. I'm always amazed at how much quieter and smoother they seem once I get them back. You really notice a difference then. And I buy top of the line, or near top of the line, machines. I have a 20 year old Pfaff 1473 I just had serviced a few weeks ago (nothing was wrong with it, it just needed a good cleaning/check-up), and it was like a brand new machine when I got it back.