I would highly recommend Dem’s place if you’re headed to London. It is not in the center (I think zone 2?) but the bus stop literally right outside makes it really easy to get anywhere you want to go. The room is spacious and has all the furniture you’d need for a short stay.
Dem is really nice, had great communication, and she even let me borrow an umbrella since it rained a bit while I was there.
As others have said, the water pressure is not the greatest but it still gets the job done! There is some construction across the street, but if you’re out and about it isn’t a big deal and keeping the windows closed helps to mitigate the sound while you’re in the room.