I think some of the newer machines need more frequent servicing. My Bernina 1230 could probably use professional cleaning and servicing every 10 years; however, I do not use her as heavily as some sewers. If I did a lot of sewing on her every day, I would probably take her in every 5 years or more frequently. Initially I took her in every year, as recommended when I purchased her. However, the last time I did that it cost my about $150 and I noticed that the technician had not even reset the upper tension to factory settings -- which he would have needed to do in order to test out all the features of the machine. I couldn't tell a difference in how clean the machine was either, because its innards were very clean when I took it in (because I was meticulous about cleaning). That's when I realized I was just throwing money away. After 15 years, however, my baby doesn't do one of the stitches correctly, plus I can see lint buildup inside the machine where I can't reach. So it definitely needs cleaning and servicing. It's just hard to give her up for that long......