I've had my 6600 since last September (08) and haven't had a lick of trouble. I probably use it between 15 and 20 hours per week. I love this machine!! I've pieced, quilted, free motion, hemmed jeans, put patches on a leather vest and lots of other stuff and it didn't blink in the least. The decorative stiches are fun and easy to do. I haven't yet tried the twin needle, but that is next on my "to try" list. I would recommend this machine to anyone. The dealer I bought it from gave me three years free maintenance and I finally took it into the shop in September just cause I figured it needed a good cleaning after a full year.