We've stayed at Platsa several times in the last few years - high- and low- season, and it's always a nice experience.
You have wonderful (uninterrupted)views across the bay to Turkey and a realy quiet location, about 5 mins walk from the nearest beach and small town of Megas Limnionas (shops, cafes, restaurants and car hire). In Megas you can use the local bus to get to Chios town and the airport, or (recommended) hire a car and see much more of 'hidden' Chios.
We've really enjoyed both the studios and the owners friendly and efficient management style.