I really liked the Zedwell! Not everyone will... but I did.
It's an excellent MODERN implementation of the "what can we do to keep costs down AND give the guest an excellent bed for the night" model.
The location was great for my wants. Outside: In the middle of Knightsbridge, VERY near tube and bus stops. Inside the hotel: You can hardly tell. My room didn't have a window, which seemed odd at first, but then I realized it helped insulate me from the bustle outside. AND the air handling was first class. Not stuffy at all. Air-conditioned. And I could choose the temperature I wanted. (I was there over the night of 22/23 July... not the HOTTEST days of this hot summer, but still very challenging for systems. And they WORKED, *well* at the Zedwell.
Room: Small. You want a big room? Pay the Ritz's prices. No TV! Wi-fi worked for checking email, playing Sodoku. Wasn't up to BBC Sounds.
(Bed: Big, comfortable, nice sheets/ duvet.)
Room lighting: First class. Modern. Well conceived.
Public rooms: No.
Shower/toilet: Again: Small. And again 1st class fixtures, good towels, plenty of hot water.
24/7 receptionist: Could not have been nicer, made me feel very welcome. If I'd fallen in with the opportunity to "pre-register" via the internet, I would have had almost nothing to do. As it was, a well designed self service mode seemed to be what they hoped for, but the receptionist very willingly and kindly did most of it for me.
Very handy for Royal Albert Hall.