I loved my stay at Karel's place. It's in a block of apartments on a pleasant square, where you can walk to the tram stop or metro within a few minutes. You can easily get anywhere in Prague from here via public transport but it's also a quick walk to the castle area - a bit further to the Old Town, but do-able.
The apartment itself is spacious and light, as in the photos. Everything appeared very clean. There is an oven, hob, microwave, and fridge-freezer in the kitchen but only minimal pots/pans etc. The kitchen has a wall-mounted electric heater and there is a wall-mounted gas heater in the lounge but I didn't need to use either in October as the apartment seemed to stay nice and warm.
The bathroom has a shower attachment on the bath but you aren't able to hang this from the wall due to the boiler being above it, so you need to hold this yourself in order to shower. This wasn't a problem for me at all and it had good water pressure and hot water was plentiful.
I didn't hear any noise from the neighbours and the square outside was also quiet. It all felt very secure and safe.
Karel was clear in his communication and met me at the apartment. He was flexible on check-in time which I appreciated as I arrived in Prague 2 hours earlier than planned.
Overall this felt like a home away from home, and I had a very settled and happy week here with everything I needed for a stress-free stay.