The stay at Ondrey's was great, although we did not stay a lot inside because there is so much to see.
Everything one needs is present, from fridge and cooking supplies, to shower gel and bath slippers; he even made an envelope with public transportation tickets that we might need, we only had to replace them or put the money back in place. He also provided some guides to the city and places to eat.
The apartment was clean and tidy, enough space and had a very modern look. And for me very important: private. Yet you are on a walking distance from the city center and if you don’t feel like walking, tram and metro are closeby.
Only downside you could say is that there isn't much light, but that didn't bother me because we'll we didn't spend much time inside because there is so much to see, and also because I like everything dark and quiet to sleep so perfect for me.
I would definitely recommend a visit to Prague and a stay at Ondrej’s.