Yes, power does make a difference. The electric toothbrushes and various other gadgets of today do actually make a difference when it comes to keeping your mouth as clean as possible. The best part is that you can choose from a variety of tools and budgets.
I read a study many years ago that stated that any electric toothbrush is better than a manual brush. The vibration is the key. The bacteria can't stand up to the motion of the bristles. As nasty as the bugs are, their cell walls are vulnerable to breakage when they encounter sonic waves and vigorous motion. This is an added bonus to brushing.
Another great tool is the water pik or water flosser. These tools use a forced water jet to dislodge food debris and plaque from in between teeth and below the gum line. The water flushes loose bacteria and breaks up the colonies formed by the plaque. This can be especially helpful in people that have gum disease and may have deep crevices around their teeth due to bone loss.
One of the newest dental power gadgets is the electric flosser. It has a small pic that fits in between the teeth and vibrates the plaque and debris loose. It may not be as thorough as a very adept flosser, however, what if you don't have perfect technique? Most people don't, and as with the electric brush and water floss, this will help disrupt the sticky formations of bacteria enough to improve the overall health of your gums and teeth.