It is located a bit outside the historic center in a much quieter neighborhood. You have access to supermarkets and street restaurant in the 500m radius. A tramway station is 200m away and gives you access to the main places in 30 minutes or less.
Kristyna is friendly and the check in/out was carried conveniently according to my schedule.
Overall, I would totally recommend it. I think that in Prague, it is probably one of the best deal you can get for the price/quality/location.
The flat is well equipped and good situated. Note, however, that it's not a long-term solutions if you are a couple and want to stay in Prague for a few months. It's rather a temporary option as it's very small for two people.