We stayed 4 nights at Ruth's, and it was everything we expected and more. Ruth was very helpful, first by answering our e-mailed questions and later by staying up until 3AM (!!) to let us in and give us a worm welcome after a long journey.
The flat is beautiful, very quiet, clean, and definitely big enough for 2 people. The shower is like a 5 star hotel (a big bath & hot water 24/7) and a cosy bedroom makes it feel like home. There's also a highly equipped kitchen.
As for the location – we really enjoyed being less then 10 minutes walk from all of Shoreditch markets, coffee's etc. And also a short walk to the tube, buses and every transportation needed.
Enjoy!