This is a good spot for one night. It is really close to a lot of the attractions and Sofia has a lot of extras (like extra toiletries for the stay). While you are right by the tram, the noise didn’t bother us…. It was more the vibration from the tracks. The bed was comfortable and window ac unit is a plus.
If you struggle with dizziness or vertigo I suggest you stay somewhere else. The floors are pretty uneven throughout the entire flat and entrance hallway. Walking with ease will be difficult as you never really feel “steady”