I use the MT-F FritzFon for three months at a Fritz box 7240. After initial difficulties the phone quite well (software version 1.2.24) works so far. Positive note are: very good display, successful menu navigation, handy and compact design, use the supplementary services (email, phone number, e-mail and caller picture), HD voice and ECO DECT mode. Rather average to evaluate are: battery power, voice quality, receiving power (had always received, but no maximum signal strength.). Let's talk about the negative aspects, which is why I forgive only three stars: low handset volume (! Much quieter than MT-D), noise, occasional calls to fail, many functions were provided only after several firmware updates - the customer as a beta tester , really wrong! Another drawback of the phone, it can only be used with full functionality on a AVM Fritz box with DECT. In addition, the caller Bildchen be stored on an external USB flash drive / hard disk! Owners of FritzBoxFon with integrated DECT phone this may be a useful addition. I want to emphasize that this review is only a personal opinion.