We stayed in Prague for 2 nights and this cozy apartment worked out pretty well for my wife and I.

Advantages...
~ Location was very convenient. Close walk to everything in Praha 1.
~ Alex and Katarina (his sister) were accommodating and friendly.
~ Bed was VERY comfortable
~ Washer/dryer in unit was helpful
~ We were able to store our luggage in their office for a few hours before leaving for the airport, which was very helpful.

Downsides...
~ It was a short walk (3-5 min) from the office (where you get your keys) to the apt itself, which can be a burden if you have luggage like we did... Luggage + Cobblestones = :(
~ Hot water went out for a half hour in the morning, which was annoying when youre trying to pack everything into a few days.
~ The shower itself is a little funny... remember to pull the shower door INTO the shower or you could have a lot of leakage like we did. You also shouldn't turn it on full blast, otherwise water goes all over the bathroom!

All in all it worked out well for us. Best thing was the location!! I would definitely recommend it.