Vibrator in a razor is just rediculous.. but I do have to tell you, the Mach 3 blows any other razor I ever tried away.. there isn't a single or twin blade that can touch it... not only did the M3 have 3 blades, but they also changed the angle of the blades and gave them a cutting edge that nothing else can touch.
I thought it was all hype too when the M3 came out... but I got one free in the mail and tried it, and I have to admit, its better than anything else I have ever used... I threw everything else away... now not only is the M3 my primary razor, I've actually bought a few back ups so I have one in my travel kit too.
I tried the Three blade but found it did not handle multiple days growth any better than the two blade. If I have occassion to skip a few days shaving, I just use an electric to take down the multiday growth and just do a quick shave after.
I still think the five blade is absurd, I think it is even more absurd that they marketing gurus put a SINGLE blade on the back for detail work.
I think the issue is really one of the quality of the individual blade. Good single or twin blades will always beat out a cheep marketing gimick.