Positives: Very clean and well-appointed with everything we needed. Communication with host was excellent. Location was convenient to Metro tram and rail (subway) stops, National Museum, and Main Train Station.
Negatives: No air conditioning, despite property description. As such, the unit felt too warm nearly all the time. To compensate for July temperatures, we had to keep windows open continually. Since it sits above a busy street, city noises were continuous and often quite loud; Metro trams, cars honking, boisterous voices, un-muffled motorcycles, etc. Even heavy sleepers are likely to be awakened often through the night. In cooler months, I don't think noise would be an issue.
Most importantly, Prague is a beautiful city with great public transportation. English communication was easy nearly everywhere we went. We always felt safe. The biggest surprises were the excellent food we had, and the reasonably priced goods and services.