Amazing location: few minutes walk to the Astronomical Clock and other landmarks. About 15 minutes walk to Prague Castle (or you can take a tram).
The place itself was clean, warm and comfortable.
You can find pots, pans, salt and etc. in the kitchen for cooking.
Communication: I mostly communicated with Patrik. Patrik quickly responded to all my questions what shows that Tomáš and Patrik are very responsible hosts.
Check in: They provided very detailed check in instructions (with pictures) and gave some local tips.
Transfer: Patrik and Tomáš can organize transfer upon request (though to take a tram or walk till the Old Town Square will be cheaper). The cost of transfer is 18 euro.
Internet: Wi-Fi isn't that strong, it disconnects from time to time.
Water pressure/supply is pretty weak, especially in particular hours.
To conclude, I did enjoy this experience and would stay in this apartment again!