The hotel itself is a very unassuming establishment with clean rooms, comfy beds and nicely outfitted bathrooms. What makes this place great is two things: location and service. The hotel is situated high above the central piazza and overlooks the whole chora and the old port. Memories of coming back from the beach, sitting on your little balcony watching the sun go down and lights in the port flicker on is something you will cherish long after you return home. The location is perfect in that it's 3-minute walk from the town center and yet, you are away from all the crowds and party noise. The service is the friendliest I have encountered anywhere, you are made to feel right at home.
When booking, make sure you ask for one of the rooms in the front/on the side of the hotel, as the rooms in the back are sans the view. The suite with its 2 rooms, 2 bathrooms, and a large terrace is very very nice.
The place has built up its clientele over the years, consisting mostly of couples. If you're looking for a party, you should probably look elsewhere.
I have stayed at Myconian Inn on every of my 4 trips to Mykonos and I'm coming back again this summer. Highly recommended.