This place is amazing...we stayed in the Matilda apartment for a week! I believe it is the best location for anyone visiting Prague...we walked everywhere to all the sites we wanted to see. Even though you are that close to everything it is not a busy street so it didn't feel crowded. As some other reviews have said it can be a little loud at night with the hostel across the street, but simply closing the windows fixed that problem.
We arranged our pick up and drop off through Jaroslav and it was perfect. Our check in was great...the host was right there to meet us and give us the keys. Check out was so simple...just left the keys in the mail slot. Jaroslav checked in with us just to be sure everything was good.
The flat itself is beautiful and very roomy. The tub is wonderful and there was more than enough HOT water to fill it (I had my doubts)! The bed is very comfortable! Cafe downstairs is lovely but usually people smoking in there so we didn't get to enjoy it much. The local recommendations for food were great...especially the Bake Shop!
If you are visiting Prague I would definitely recommend staying here! One of the best AirBNB's we have stayed at.