I rarely use mine. I prefer small needles for most of my sewing and the auto. threaders will not thread a needle with a small eye. At the one and only ME class I attended, I was "highly encouraged" (to put it as politely as I can) to use the needle threader every time I change colors in machine embroidery. The dang thing really likes to shred the embroidery thread, both rayon and polyester. Also, I can thread the needle myself quicker than the auto threader can do it. Some people swear by them and love them, but not me.
Two of my machines came with knee lifters and I never use those either. I believe you can teach old dogs new tricks, but the knee lifter is about as irritating to me as is the auto. needle threader.