Not living in London or the UK, but working from London a couple of days a week most weeks. I looked into living in London however the high cost of living scared me, would be very difficult to have the lifestyle I have in The Netherlands there. Also I am afraid my savings would go down the drain, literally, I am too fond of pubs and real ale...
I do know a number of people with nice apartments in central London who never have to work again at 45, if you work(ed) for the right companies there, I think the sky is the limit.