We had a recent very enjoyable stay at the Altstadt hotel in Vienna which is part of the SLH group. It is well located - not more than a 10 minute walk from the centre of town with great local restaurants. Like many SLH hotels, it is slightly quirky - housed in an old residential building with funny shaped rooms but the staff and service was great, the breakfasts fantastic and they also offer complimentary tea / coffee / snacks in the afternoon. It was pretty good value as well.