I think a factor that is often overlooked is that the driving force behind new technologies is sometimes not solely that the new technology is better (if indeed it is!). The cost and efficiency are a factor and perhaps why we are being pushed towards it. It is likely to be more convenient and cheaper to maintain a phone system that is integrated into the broadband network rather than one that is separate. In this case there is also the billions of pounds worth of copper that could later be dug up and sold once all are on digital voice. In these cases the new technology merely has to be acceptable for the most part. In terms of functionality most people are not likely to use all the new capabilities of the digital phones- we can already find who called last, block numbers and have short code lists for quick dialing for example and don't think we will use much else. The need for a power back-up if the electricity goes down and to replace batteries periodically are disadvantages in fact of the new technology but ones that are only likely to affect most people rarely enough that change can be pushed through.
