I bought my pfaff hobby 919-1 about 17 years ago.
I sew really everything on it: clothes, quilts, curtains.
And use it a lot.
As I asked my dealer/serviceman about coming back every year, he told me I didn't need to.
he said they only clean and oil it, things you can do by yourself...only when it doesn't work properly anymore they can repair it.
So I clean and oil it myself, and I had several friends over that say my machine works smoother, with making less noise as theirs