What a bargain! Right in the middle of Prague's picturesque old town and huge! The area is great and the building has three doors to get in, so you'll feel quite secure.
The apartment has some beautiful old and super-high ceilings, cool exposed brick walls, a modernised kitchen, and a couple of amazing bathrooms. The wifi is good, as are the heat and hot water. The bedrooms sleep several people, biggest has five beds and the others a few less each, so you really can sleep a lot of people here - perfect for a group trip. The beds themselves are low futon-style but quite comfortable. There's no hanging space or dressers, though, so you'll be living out of your suitcase - a small price to pay given the quality of the rest of the place.
Frantisek was an excellent host. He was very communicative throughout, sent along a long list of Prague suggestions, and easily accommodated our earlier than expected arrival.
Great all around!