Less power of the new models - intent?

Video at Amazon.com See I bought in May 2013 an Oral-B Advance Power and was very satisfied with the quality. The performance came on the rechargeable Oral-B toothbrushes. Well, it has no timer, but the convincing argument for me was that it is running with normal AA batteries (or rechargeable batteries). She does also reliable for several weeks with the same set of batteries. I was tired to put every two to three years a lot of money in a new electric toothbrush, simply because the permanently installed battery no longer holds its charge. Once I tried a battery replacement, but that has brought only six months.

Until then, there were at least four stars, probably even five. I wanted to buy the same toothbrush for my wife again and have them re-ordered from Amazon. But when you turn I immediately noticed that it runs much weaker. With fresh batteries supplied it was underpowered as the previous brush with low batteries. I thought of a defective device and have returned it. I have since ordered another copy from Amazon and a buy at Rossmann. But even these toothbrushes ran as weak. Even with a bit of resistance, the electric motor to its knees. Absolutely no comparison to my first Oral-B Advance. Of course, these toothbrushes also fell back.

I would not have my first Oral-B Advance as direct comparison, I would probably think that they just do not come close to the performance of large, rechargeable toothbrushes. But I know that it comes in principle.

My suspicion: Oral-B throttles intentionally performance with the current models. Otherwise I can not explain the major difference. Because with a reasonably functioning quality control would notice immediately, it will therefore certainly not be just a faulty batch.

I'll ask the manufacturer, making this huge difference between the model from May 2013, and three tested models from this year comes. Should I get an answer, I will add it here.

Addendum of 27/01/2015:
At first I had written that my message on the Facebook page of Oral-B has been deleted. Obviously she was instead classified according Oral-B of Facebook as spam, because it was a little longer. The answer I got is the following:
"To the technical part: an inquiry with our development department has revealed that changes were made neither on the design nor on the performance of the installed motors."
Unfortunately, this explains so do not know why then lie between the first purchased toothbrushes and three other copies that were purchased a year later, worlds in terms of engine performance. I am now switched to a competitor's product and been very pleased.

Addendum dated 31.03.2015:
I have a short video supplemented where I compare the original model with a newer model. For this I use the same set of batteries, or batteries. You can hear the difference clearly, in my opinion.