The apartment is perfectly suitable for 4 people. The sofa bed is not the biggest but two people not taller than 185cm can fit easily (it is quite comfortable to sleep in). The large bed up top is really comfy - however the ceiling there is not high so it’s not possible to stand up straight. For us this definitely wasn’t a problem, but it might be for elderly people. The bathroom is really nice and the small kitchen is big enough to at least cook some small dishes. The location is in Charlottenburg and close to Kurfürstendamm. It’s quite close to TU Berlin so that was perfect for us. Check-In goes smoothly via a lock on the door so you can arrive whenever you want after 1pm. Definitely can recommend staying here!