Phillips Sonicare 4100 Toothbrush Model HX369W1

My old Sonicare lasted only two years.
I bought this on Amazon for $39.96. The power button is rather odd, if I hit it twice rapidly the second speed seems slower than the first. If I wait a second and then hit the power button a second time the second speed is faster.
The deal with the registration card is that once you register they will extend the warrantee for a few months. About the free brush head, in order to get a "free brush head" you have to pay one penny and sign up to subscribe to buy a new brush head every three months.

https://www.youtube.com/watch?v=dYRMl6XanWM

https://www.youtube.com/watch?v=cfA3j0hMyAw