I have the 6600 and do have several issues with it. One is the tension does not stay consitant and I feel it takes up too much of my time to get it set right so often. It does seem to be that they could have done a lot better job with the uptake lever for the thread often pops out of it and makes a mess. I also don't like the way it leaves a nest of thread when srting to sew. It is heck trying to get the lower thread to pick up so it can be put to the side along with the upper thread. Personally I like piecing and quilting with my Juki so much better. The dealer I bought from is no help at all and had I known that, I would have bought on line and saved some hard earned money. JOPO