We stayed here as a family of four adults. I would no hesitation in recommending.
The location is great - easy 20min odd walk to the centre (note it is uphill all the way to the centre but not onerous) as well as right by Stockbridge and the various restaurants it has to offer (we liked Hector's best).
Very handy also for (free & lovely) botanic gardens as well as Water Of Leith walk (45mins odd takes you to Leith)
Apartment itself is very nice. Lounge has two comfy sofas, table and large TV.
Easy for four to eat in good sized kitchen. Large bedroom excellent, smaller one, cosy but fine for two.
Two minor issues would be size of sink in shower room which makes shaving a bit of a balancing act, but no big deal. And the dishwasher is sub-optimal - again, no big deal and neither of these would prevent us putting this first on list for our next Edinburgh stay.