What is interesting is that one is allowed to use a tweezers on the beard and pull out the hair and the root entirely. Melaket vRahitni are the terms used, I seem to recall. The reason is that that is not called shaving.
The issur is only when one shaves down to the root with a single blade. Let us think about it for a second. In order to cut, there has to be a back pressure keeping the hair still for the blade to work. If one uses a razor blade, the back pressure is supplied by the pores of the skin keeping the hair from moving backward while the blade cuts it. Therefore the cut is at skin level. When using a shaver, the back pressure is supplied by the screen which props the hair up so the blades can cut. It does not reach to the skin. That is why it is a scissors-like action which is OK.
I think the only problem is the rishonim who say that one does not need to go all the way to the root to be a problem. I do not remember. The sources are on koshershaver.com. I commend him for being intellectually honest and bringing the sources for both sides. One can really gain an understanding of the sugya if he reads the Hebrew footnotes on the bottom.