I think that part of the equation in selecting a sharpening system is:
1. Japanese blades or Euro style? Each have a different angle for sharpening. Choosing the sarong angle for your blade will - at best make it harder to sharpen - or remove so much metal to correct - that it reduces the life of the knife.
2. Cost of the knives you plan on sharpening. If you knives are moderately priced knives - then there is not so much risk. If your knives are very high quality, and thus - high in cost...I would not trust them to affixed angle electric sharpener. There are too many good professional sharpening services available. They are not expensive - and there is typically a guarantee of quality work by the sharpening service.
3. If you REALLY want to sharpen knives on your own as part of the craft of cooking and - if the lives are fairly pricey ones - you may want to consider the Wicked Edge system, or a V-Sharp Classic III - or KME - or even an Apex system. These are all adjustable angle, repeatable process manual sharpeners that can create "shaving sharp" blades. Of course - they depend on you to read, practice and gain skill. But they do simplify and accurize the task .
Really - there may not be one "best" answer. You may have knives that you sharpen on an electric. And - you may have some that you have a professional sharpen for you ( Williams-Sonoma stores always have a service for this.)