Josef's flat is perfectly located in Praha. It is a short 300 yards from the train station and maybe 100 yards from the main plaza in Old Town. They are very trusting people. You are given a key to the gift shop, which you must walk through in order to get to the stairs which take you to your room. If you come back after 11:00 pm, you'll need to pass through with no one there. No problem with this, but very unusual. Josef is very accommodating to your needs.
The beds were comfortable and the bathroom was updated and in great shape. He gave you a very thorough Prague guide book with everything you'll need for your visit from restaurant suggestions to parking options to place to see while there.
There is nothing I would have changed with our visit. I'd stay here is a heart beat. His helper, Natalie, was a peach. She is a beautiful human being who also was very helpful.