The room is clean, bright, and spacious, and is equipped with blackout curtains for early sunrises (or afternoon naps :) ). Norbert was very responsive and helpful with my questions, including with advice on how to get from another city to this apartment as well as any clarification that I needed. Everything from bed linens to towels to laundry soap was provided, and having full access to a kitchen and its essentials is very handy for being on a budget. As a bonus, the building is also beautiful, and to get up to the room you get to walk up a spiral staircase.
A word of caution is that the location is ~20-30 min outside the city center via public transportation depending on traffic and time of day, so it's easier to plan to be out for the full day instead of thinking you can maybe take a break in between museums. The quietness also depends on the other guests in the building—it caters mostly to student-aged people, who can be noisy late at night, and the building carries sound very easily.
That aside, it's certainly more affordable to rent this apartment and buy an unlimited-use transit ticket than it might be to stay elsewhere in the city center, so it might even out at the end of the day depending on what your goals are.