Well-renovated flat in a not-so-renovated building, i.e. don't expect great insulation or air-tight windows. However, plenty of heating power is available once you figure out how to set up the Nest thermostat properly (tip: move it further away from the radiator!)
The location is great and extremely central, but that also means significant noise/activity day and night, so not a place for light sleepers. The well-equipped kitchen and the overall size make this a great place for longer stays, but only if you're not a movie enthusiast - the TV is cleverly hidden inside a cupboard which obviously limits its size and comfortable viewing positions. Internet/WiFi is OK, but not stellar - zoom occassionally had issues.
One nitpick: the airbnb flat doesn't have access to the property's waste collection bin, and the next public one is a few hundred meters away. Not a far distance to walk in itself, but quite a far distance to walk with a full bin bag!