Yes, I found it really brilliant. For one thing, you don't have to be able to identify and deal with the lice. You just comb, you hear a change in the tone, and you know you've zapped one. (Well, sometimes you get false positives, but usually a change in the sound means there was a louse.)
Also, you can use the electric comb on yourself quite easily if you don't have another adult willing and able to check you or get rid of your lice. Unlike wet combing, you don't really have to comb through all the way to the ends of the hair, just the area near the scalp where the little devils like to hang out.
I first started using the electric comb on a very active two year old, and I liked that I could just have a go whenever - no need to get hair wet or conditioned and have a big session. I'd do my child for ten minutes or five minutes or however long they would sit still. An hour later, I'd have another go. And so on. This is less effective than systematically working your way over the child's entire scalp, but that was never going to happen with this particular child! I figured if I had a go umpteen times a day, eventually I would get all the little blighters.
In common with other methods that only kill lice and not eggs, one session isn't enough. You have to stick with it and keep zapping newly hatched babies before they have time to mature and lay eggs. In time, you'll get them all.
I did find the high pitch slightly annoying, but it was worth it. I guess if your child is sensitive to that sort of noise, they might refuse it. Also, I should think that electric combs would be unsuitable for use by people with hearing loss in the upper ranges. Older people often lose the ability to hear higher pitches first. So they wouldn't know if the comb was working and whether it had zapped a louse - you have to remove the body before proceeding.