We booked a two night stay at high Street Suites, which was amazing! Marc was so helpful and always replied very quickly.
The Apartment was very clean and beautiful. The location itself is perfect if you want to explore vienna, but also go out for some drinks or do some shopping, as the Apartment is surrounded by a lot of shops, very good restaurants and bars.
If you are looking for a modern Apartment for 2-4 people, which is in a perfect Location, I can definitly recommend high Street suites ;-)