Phone well, writing and numerical representation problematic

I bought because of the good reviews me the phone. What stands in the previous reviews is already correct. However, for me it's important, as well, the display is readable. Writing and numbers are shown very small, nothing for older people or sehschwächere. The white letters on a dark background is still ok, but once you go to the search in the phone book, lies down on the selected entry a light blue ribbon, so you can hardly see writing and numbers. This is a ko criterion, therefore only 3 stars. Furthermore, in the description no indication as to whether the handsets can be registered in other foreign base stations. You have to try it. Toll I found that the items were immediately transferred in the phone book at Duo automatically on the 2nd phone.