Almost ten years ago I bought a Siemens Gigaset for my fixed phone at home. It consisted of a base station ("Gigaset 2060ISDN") and two wireless handsets (“Gigaset 2000Comfort”). A year later I bought an extra handset. Now several years after – and several Gigaset-generations later – I bought two extra handsets ("Gigaset S44"). It’s amazing – despite the many years between the models, they just work seamless together with the same old base station. Besides the basic phone (which uses the DECT/GAP standard) even copying the phone directories from the old handsets to the new works flawless.
It way cool and it rocks. Besides being rock solid technology which just works, it’s amazing that you can keep utilizing a ten year old base station – off course the new features in the new handsets which didn’t exist in the old models doesn’t work, but that’s hardly a surprise.