I couldn't imagine better place to stay and better host in Prague.
Ondrej clearly put lot of thoughts in to how to make you feel home.
One of the first things you will remember about Prague after you left will be Ondrejs friendliness if you meet with him. He answers all the questions you could have before you even ask.
The apartment is in the heart of Prague.
Very very clean, comfortable, modern and walking distance to all the must see places in Prague.
I would highly recommend this place.