I stayed at Mikuláš’s place for four nights over New Year and had a great experience. The apartment is well-located in a residential area just across the river from the city centre. It has a more local feel, but is still just a 10-minute tram ride to the start of the Old Town. The area by Prague Castle and the main train station are about 15 minutes away on the tram. The tram stop is ideally located less than a 5-minute walk from the apartment, just next to a small convenience store. The journey from the airport was straightforward too (about 45-60 minutes on the bus and tram).
The room is a fantastic choice for independent travellers. It is made up of a living area with a sofa, desk, wardrobe and a small separate side room with the bed. There is also a private toilet just across the corridor. Just the kitchen and shower are shared with the family, so there is lots of privacy if you want it. Both the bed and living area have a separate radiator which always worked very well - incredibly important as it was freezing in Prague in late December! The rest of the flat was spotlessly clean and always warm. The wifi worked well, although the signal does drop slightly in the bedroom area.
I didn't meet Mikuláš in person, but communication during the booking process was very smooth. He provided good directions to reach the apartment from the airport. Mikuláš’s mother Zuzana, her friend and his sister Klara were extremely kind and helpful, making me feel very welcome. They have a cat and a dog. Both were nice pets, although the dog could be quite boisterous and hyperactive at times, which is something for potential guests who aren't particularly used to dogs to bear in mind.
Overall, I had a great stay at Mikuláš’s place. I found it a very good value-for-money option at an expensive time to visit Prague and would certainly recommend it to anyone planning a trip there.