The flat is very clean and spacious, perfect for a couple to stay and enjoy all that Prague has to offer. :) Martin is a very kind and helpful host, he showed us around and told everything we needed to know.
It seems that the flat is a bit far from the city centre but the comfort of it is certainly worth it. Also, you can use public transport while in Prague (3 days tickets are the best option). Take any bus that leaves from in front of the building and travel to Skalka station where you can enter the green line of the Prague's metro - and you are good to go and visit any tourist attractions from there.
I recommend this place to stay if you want to visit Prague. :)