When travelling with a large group, this place is fantastic. The value for money is good, and it is only a 15-minute walk into the Old Town. Communication with the host went smoothly and in general what you see is what you get.
The only minor improvement I'd suggest is a little more focus on basic amenities. Things like salt/pepper, dishwasher tablets etc ought to be complementary.
Great trip and great stay overall - I will definitely go with Petr again next time I go to Prague!