Good article and he comes across as being a nice guy who actually cares about his staff, customers and his product so I think he can be forgiven the idd slip up, perhaps he may have meant infrastructure wise when he mentioned companies being based around London?
I have to say I've moved around quite a bit and tried the cheaper ISPs (as you'll see from my sig) but Zen has always been the best and I wouldn't move again.
As regards Demon. they were a London based firm (Finchley I believe) which were bought out by the Scottish Telecoms operator Thus which have been acquired by Cable and Wireless.
Eclipse was started in Exeter and was acquired by Kingston Communications.
Virgin (ADSL) => Namesco => Newnet => O2 => Plusnet => Zen => Newnet => Zen Lite 8000 (I'd like to get in on the FTTP trial)
Note: I don't lay turf for anyone. astro or otherwise, all views and opinions expressed are my own based on experience.