The apartment is awesome and exactly as described. Especially the beds are very comfy and guarantee a good night's sleep (most important for me). The location is perfect to explore the city and there are many great restaurants closeby.
The only downside was that it was a tropic 30°C inside when we arrived and there is no possibility to adjust the heating. However, Alex came the same night and adjusted the heating at the central unit to a more bearable 24° which was still too hot for my taste, but again, OK.
It was not part of the Airbnb, but we booked an airport transfer over the host's homepage and it failed. This was actually a big deal, as you cannot easily get a Uber/taxi with a toddler (you need a baby seat) and we were really lucky that we finally found a Uber driver who would take us without having a baby seat (which is not ideal, but better than to be stuck at the airport). Worst of it is that we only found out because I called them after waiting for some time at the gate exit with a crying baby. At least I would expect a notice that the transfer does not pick us up.
However, we had a great time in Prague and the apartment so that I would come again to Alex+Kate (with a heads-up on our temperature preferences ;-), but book the airport transfer somewhere else.