We came here at the beginning of the season and it was quiet, but we thought our one night stay was excellent. Our second floor was bright and airy, and the views to the east across the lake were fantastic. The bathroom - shower only - was fine, but basic, and those annoying sachets of shampoo and tiny packets of soap a a bit of a let down. Dinner was very good and presented lake fish well. Breakfast was also good and with plenty of choice - and exceptional service.
The highlight to me is staying on a small island, and waking to those spectacular views. The evening v morning light make a huge difference to the way the mountains and lake appear. In our view the place was excellent and we slept deeply to the sound of the lake outside. For room choice, I think I preferred our 2nd floor lake view room with the small two seater balcony on which to sit and marvel. The larger balcony is right underneath and lacks privacy, and means the room is some way back.
There are several places to eat on the island - which is small (we walked around the whole island in 15 mins) - from larger formal restaurants near the pier to tiny back street cafes. Have your camera ready on the ferry as you approach/leave too!