Matthias was very welcoming and extremely helpful! Any questions we had the whole time he helped us :) He gave us detailed directions to his house and always replied to messages quickly, he came and met us at the door when we arrived and before we left made us dinner! The room we stayed in was very clean & spacious & had lots of big mirrors & desk & table! The shared kitchen was clean & nice & we were welcome to use things for cooking. The bathroom was also very nice.
The area is great, right next to the famous Saturday morning market and lots of places to eat in walking distance. The metro is only a 3 minute walk away and there is also a bus right around the corner that takes you straight to the train station. Also there is a City Bike rental station right next to that metro where you can rent bikes for $1/hr!
We will certainly stay here again if we ever come back to Vienna!