This is an absolute no-brainer if you want to stay central yet have a good sleep. The house is on the busy street right after Charle's bridge, however as soon as you go in its silent like in the countryside.
The house itself not big but has everything you need for a comfortable stay, and it's very warm ( a big plus as we were freezing outside), all the attractions are in a walking distance. Also just under the building is the best Trdelnik place (imho).