Marčela and Sebastian's apartment is well-designed and well-located. We loved the decor (and the great storage, especially for a longer stay!) in the apartment, which feels spacious for two. The location was perfect for us - walkable to the most popular sites but well away from the crowds, quiet and neighborhoody, close to many great local cafes, shops, an awesome farmers market, and parks. I've spent a lot of time in Prague and their apartment allowed us to discover a new and very cool part of the city. Marčela and Sebastian were both very nice and met us in person, were flexible about check-in and check-out times (very helpful!) and readily available.
Things to note: it is a basement-level apartment, and we found it a little damp/dim. It was rainy during our stay so this may have contributed to that! The bed also left us a little stiff, although it is nice and big.
Overall a good stay and a very good value for the size and location of the apartment.