I got the Mach3 Power, but the battery was dead when I bought it. Used it for a week before replacing the battery. Replaced the battery since, and overall it's a great razor. It gives a good clean shave, but I didn't notice any difference in the shave with it powered up. Also, the blades themselves don't seem to last very long before needing replacement, and if you don't replace the blade frequently, it feels like it's tearing the hair out of your face as opposed to actually cutting it.