The flat is wonderful. Clean. Modern. Great bathroom. Good fast WiFi which made working from the flat easy.
New and working heating (air con looked good too, but didn't use). The kitchen was very new, well stocked with equipment.
Bed was large and comfortable. Shower high pressure and lots of water. New fittings.
Check-in was flexible (which is very helpful for a late flight).
The only down side, hence 4 not 5*, is that the road is very noisy, both from traffic and late at night people. The windows are quite good, and the flat is well insulated, also the neighbourhood is fantastic, so I think you must expect some noise being so conveniently placed. But it was a bit of a distraction on a couple of nights.