Me and my boyfriend stayed at Nissia for 3 nights at the end of August.
The hotel is in a very good location to stay and walk around Spetses and you can easily walk to the nearest beaches.
The room was nice and clean, with a kitchen to use if you wanted but definetely not worth at all the 220 euros per night. Very overvalued.
We were also disappointed by the breakfast - and again this comes relative to the price we paid.