Nice apartment for groups. There was plenty of space everywhere for our group of 8 people. Location is awesome, very close to the old town centre and public transport, which made getting anywhere very easy. The apartment is in an older building, so it comes with some of the expected things related to it, like squeaky doors sometimes. But in a city like this, how much time are you spending inside anyway.
Host is great, we had some items that we couldn't find and he had it sorted by the next day. Also has great suggestions for places to go, be it for activities or food/drinks. Check in experience was very easy. We used their self check in procedure and got very clear instructions with a video on how to get our keys and into the apartment.
All in all I would recommend this to any larger group for a nice stay in the centre of Prague.