The rotary sharpener does not work for me, but works fine for DH, if he is in the mood. I am sure his more muscular grasp makes the difference.
I am not much of a gadget person, partly because I simply do not have the space. I bought the bobbin winder, which was a great asset when mine broke, but after repairs, I passed it on. (70 miles to the dealer)
My Bernina was my bigest mistake. It gave out in 3 years.