At first I was very skeptical because I had some sinus models (http://amzn.to/1M8a2V9) Telekom already and all were underwhelming. The Speedphone but lives up to its name: it is pork quickly in navigation. The display is very high resolution (pixels can be seen yet, but it's just not a cheap display) and highly luminous. The rubberized buttons are a decent size and can be very good press. A slipping is not here. Since the buttons are also seprariert, a blind operation (for Senrioren or people with limited vision) is possible without problems. For missed calls the upper right button will flash very bright and clear. The battery life is good. The device was easily connected to a Speedport W724V. Speedphone turn on and press "Next" to "Login" button on the router, finished. Number assignment also worked without problems.
So what more could you want? I would hope that more people call me on the landline instead of on the phone. ; O)