Stay here!! This apartment was absolutely perfect for our trip. It is located on Karlova, which is the most touristy street in Prague, which for us was great. It is just one block from the old town center and 5 minutes from Charles Bridge. The tram is only 7 minute walk, so we were able to get out of the touristy areas and get to two different parks very easily.
The hosts were fantastic and in addition to meeting you at check in and telling you about things to do, they have two very specific books, one written by them, on Prague. We used these and all of our meals were great.
The apartment itself was also perfect for our group: four adults and two kids. We hung out in the living room and ate dinner on the patio. The house was sparkling clean and beds were comfy with coffee (!!!) left out for us. We would most definitely stay here again.