We were a group of 6 (2 adults and 4 seniors), and this was a perfect stay for us in Edinburgh! Given how crowded the city was during the Fringe Festival in August, the location was as close as we could ask for to the city centre (~12 min walk from St Andrew's Square) without being too noisy at night. The apartment wasn't too stuffy, hot or cold either!
Our host (Callum) was incredibly helpful! He offered us advice on food and things to do in Edinburgh without us even needing to ask. His check in and out instructions were crystal clear, and he was always responsive when we needed to ask him about stuff.
Just note that you have a few stairs to climb so it was a bit hard for my parents to carry their luggage when we checked in and out, but I could manage with their bags. Everything else was perfect!