Does anyone use them? Are they worth the cost, and what kind would your recommend?

If you mean the rotary blade sharpeners, my experience was not good. I used it several times with very poor results. I finally threw it away.

I sometimes use mine to resharpen once but have found that the use time for the resharpened blades is short. So now if I have one little nick, I'll use it and then throw the blade away when it begins to give me more problems. I wouldn't buy the type I have-the round kind you drop the blade in-again. It's much easier and satisfying to toss the old blade and start with a new one.

Must have double-clicked on the send button-sorry for double post.

I am not a fan of them. Mine has sat for some time after using it a couple of times.

I do use one - & do like it.