My mum and I really enjoyed our weekend in Edinburgh staying at Sinan's place. It's so easy to get to the house. If you're coming by train you're probably best to get off at Haymarket. Only about 10 minutes walk to get to Princes Street and there are various supermarkets and cafes very close to the house.
The house itself is really comfortable and would not feel too small if 4 people were staying there. Perfect if you are wanting a relaxed weekend away but this probably wouldn't be right if you wanted a lively, loud holiday as it is a quiet neighbourhood.