I love the start/stop button and reverse button. I am disabled and cannot manage a foot pedal nearly as smoothly as I'd like. A few seams and I have a rhythm already set with my thumb operating the buttons while my other fingers hang on to the piece I'm sewing.
I'd give it a "5" but I haven't tried all the features yet, so the rating is based on straight and zig-zag sewing.
I'm going to love this machine!