An MPEG4 box inferior to and MPEG2 box? Weren't you the one hounding them for ditching that? And you have hit the nail on the head... it was dropped because TW's had already launched theirs and there was no point working on two different technologies. And whether or not it was 'working' is debatable
NTL did actually instigate the very first round of broadband speed upgrades. Telewest followed their lead.