This is a really great apartment in a very convenient location just out of the centre of town. If you're coming via train or plane it's particularly useful as it's just over the road from Haymarket station (which most trains stop at before Waverley) and the tram stops.
We went in summer 2020 so paid the festival rate despite no festival. During a normal year however it would be really good value.
One caveat: the front two rooms were really noisy and there was lots of activity in the road outside both nights. It didn't bother us massively but if you are sensitive to noise it might bother you. The back double rooms were nice and quiet however.
And one recommendation: coffee and buns from Twelve Triangles bakery (a 5 minute walk away) were a great way to start the day!