Safe, quiet, central, convenient.
Ondrêj was a great host. He waited for us even though our flight got in late at night and made sure we were well acquainted with our surroundings and knew where to find everything before leaving. He speaks excellent English, which was helpful since we're hopeless at speaking Czech!
The room we stayed in had 20' ceilings and was part of an old library. Very cool. The bed was comfortable and the heaters kept up despite the large space.
I believe it is typical for this area but just so other tourists know, there is a tub and a shower head on a hose but no shower curtain. This means you end up taking a bath or showering sitting down. Not a big problem, just unexpected.
This is a FANTASTIC location. It made Prague seem small because we were so close to everything. There is a tram stop right outside the door, metro (underground) stop around the corner, all night food is available from several places on the street including gyros, sausages, fried cheese, and fries. There are several nearby bars and one of them is run by an American so it has the NFL Red Zone channel (5 minute walk and Ondrej gave good directions).
Despite being in such a bustling and noisy area the room is completely silent, buried in a deep courtyard.
No complaints with our stay. Really great place!