Ali, I had originally thought that a thread cutter was unnecessary . . . UNTIL . . . I got my 6600P. Now I can't live without it! It really saves on thread as you only are left with 1/2" tails. No more groping for the scissors somewhere under your work! :-) The knee lifter - well after 5 years, I'm getting better at putting it to use! My first sewing machine after getting married was a Singer Golden Touch 'n Sew in a desk cabinet. It had a knee bar that pushed on the foot pedal wedged into a holder. Even now, some 40 years later, I keep wanting the knee lifter to make the machine run!!! It's wonderful for appliqueing as you can keep your hands on your work & use your knee to lift the presser foot when you need to pivot.