I've had my 6600 P for a couple of years and love it especially the needle up/down. I don't use the Accufeed as often as I'd like to because I haven't figured out how to keep an accurate 1/4 inch with it --I prefer to use the 1/4 inch foot. Haven't tried FMQ yet but did purchase the special bobbin case in order to do FMQ. Info from board members said one would avoid problems using the special bobbin.