I have a 4800QC Janome and have had it for 7 years now. I love it and it has never given me any problems. I can only tell you that from my experiences at the retreats I go to and from my exerience with my cousin who has the top of the line Bernina, they are always having problems with the bobbin being wound right or the needle being in right or the tension being too loose. The only people at the retreats that have problems with their macines are the Bernina contingent. My cousin was constantly needing instruction on how to sew with her machine. The feed dogs wouldn't retract when necessary. I also take classes at a local quilt shop that uses Bernina's and have used them. They are not easy to learn.