All in all we had the perfect experience at John and Diego´s place! The communication was great, John sent us a lot of useful tips in advance and gave us a lot of recommendations for wonderful markets (Columbia Road Flower Market / Broadway Market...) and restaurants, but also practicals advises for using the underground, getting to the airport etc.
Their flat is amazing: It is cozy, stylish (we would move in right away) and clean, we had a feeling like beeing at home. And that´s also because they made us feel like that with their warm welcome and our conversations. Also the location (Shoreditch) is great: You can experience a lot of different restaurants, cafés, markets, vintage shops or just wander around and let everything sink in.
So all in all: We would definitely come back and would be happy to see you guys again (maybe in Vienna?)!