Had my first 2 new Speedphone 10 ordered because I was of the opinion that these devices work optimally with the Speedport 921V. The then worked well, but the devices themselves were a disaster. Have they returned and ordered me the Gigaset C430 A Duo. What can I say, like night and day to the Speed Phones. Much better voice quality, better service, more and better ringtones, much greater functionality, much greater range and the best, significantly longer battery runtime.
I am very pleased with the Gigaset and recommend it to anyone.