My girlfriend and me had stayed at Sebastian's place for 4 nights, with the focus of our stay exploring the city and looking for an apartment prior to moving there, which required a lot of moving around. The location was perfect, with quick access to public transportation towards different parts of the city, and in proximity to ETH. It was also convenient for us to walk to the lake and the old town, as they are not far (on the way back there is a bit of going uphill which we didn't mind, although it can be avoided by using public transportation until quite close to the apartment for those who aren't keen on walking uphill).
The check-in procedure was simple and smooth, the place was clean and tidy for us, the bed is comfortable and the communication with Sebastian was quick and efficient. While there is no kitchen, the place has a small and convenient setup for hot drinks and a simple breakfast (muesli etc.), which we used without any issues.
We can highly recommend Sebastian's place, and would be happy to stay there again.