I have one and I’m in London. My understanding is these new rules actually free things up significantly for drones in that weight class. Previously, you couldn’t fly over ‘congested’ areas, near people, buildings, etc. So it was very difficult to fly fully legal around London. The new rules remove those restrictions.

All they require in exchange is registration for £9/year. The sub 250g drones don’t require you to do the online certification or get a flyer ID.

London still has a bunch of special security zones you can’t fly in, so you won’t be getting any nice shots of Canary Wharf, but it does open things up a lot. I’m concerned that the police won’t be up to date with the new regulations though, and apparently they can just seize your equipment and make it very painful to get back.