Most of the Chef's Choice sharpeners are pretty good for the right person in the right situation. If you're the type of person who can't or won't learn to use benchstones skillfully; can't or won't use an expensive tool and jig like the Edge Pro; and can't or won't find someone to take care of your knives for you as frequently as they need care -- they're the best option. Better than a Sharp Maker, better than crock sticks, much better than a carbide pull through, much much better than expecting a steel to also sharpen, etc., etc., etc., all the way down the parade of horribles.
They aren't perfect, don't last forever, require some cleaning and mainteance, and aren't the best or even the second best solution to "the best possible edge," but they work well enough and are convenient enough to use often enough that you'll have sharp knives.
Not to beat a dead horse, they're as good as it gets for quite a few people.
Most of the other electric systems of which I'm aware (and that's quite a few) won't work nearly as well for most home users.
If you're asking about using an electric sharpener for your own knives you can get a better answer by describing your particular situation rather than asking so generally.
BDL