The flat is very fine. It's clean, in a good location with 3 tube stops near by, with all the basic amenities.
The key pick up/drop off works, but it's 10 minutes away and is just annoying schlepping your stuff back and forth.
You don't deal with the owners, but a service. They're great at checking in on you but are hit or miss depending on who helps you. 100% my fault leaving the one and only key in the flat. When rep #1 never called back as promised, I called again and the woman was very helpful and arranged another key at the divey convenience store that the first rep said they didn't have.
One of the showers gets only lukewarm and the rain head sprays water all over the room. They checked in to see if we were still having problems, but never offered to come fix it.
All in all it's a fine, clean place to stay. The key issue is enough to find a different place these days, imho, and if you were 2 couples the shower issue would be unacceptable.