We stayed at Haus Lenz for three very restful nights. The initial climb with luggage was enough to make us pant. Without luggage, it's just a steep walk. The benefits of being high up on the Hallstatt hill are the view, and the quiet. After about 10 pm, even with the windows open, we couldn't hear a single thing.
The room was very comfortable and homey. The bathroom was spacious, but ran out of hot water very quickly. Unless you enjoy cold showers, don't be the last to shower in the morning.
Helga is very pleasant and helpful.
Breakfast is good. There is no WiFi.
If you're looking for a comfortable and restful place with amazing views, it's hard to beat Haus Lenz.