Hi Cupped. If I understand your question, you're looking for opinions on the difference in quality that a manual grinder and an electric grinder can provide. It would need to be known if the electric grinder you're referring to is a blade grinder or a burr grinder. We know that burr grinders provide a more consistent grind size and don't just shred the beans to uneven bits and chunks. I'm already assuming the "hand cranker" you're referring to must have conical burs and not blades... otherwise, heh, that would be kinda weird.
My take: When it comes to burr grinders, you will receive a more consistent grind,
regardless if it's a manual or an electric. There is a difference though,
IMHO. If you'd like to experience the more romantic side of something you enjoy, you would choose the more hands on approach and not the quick & easy push button experience. When using my manual grinder, I get to hear the individual beans exploding under the pressure of the burrs. Five minutes and 600 cranks later, I open the little drawer to find a nice little pile of fresh & aromatic coffee grounds that is just enough to brew up one nice big mug of my favorite single origin coffee. Of course I don't do this all of the time, but I think it's important to be a part of the process once in awhile.
Another difference is a manual grinder is usually less expensive, the size is smaller and more convenient to transport and can be used anywhere. You don't need to keep it near an electrical outlet. Both electric and manual grinders have dialing adjustments to get the proper sized grind to match your preferred brewing method, from very fine to very coarse (and all in between).
For home use, I'd say why not have both?
