The location is excellent. Very easy to access from the airport using only public transport and a one minute walk. From there, you can walk anywhere in Prague. I was there for three days and did most of the major tourist things, and only took the metro twice - from/to the airport.
The flat is lovely, exactly as per the description and photos and extremely clean.
What really stands out, however, is Mirko’s tips. He was a really engaging host and very helpful, from well before I arrived in the country. He offered a variety of local insights, tailored to my own interests, on subjects covering the sights, food/drink, nightlife, and getting around. Would definitely recommend.