Well i will say that i have only been Plakias once in 2000, but me my bro and my dad stayed in Alianthos Beach, and it was very nice apart from no fridge nor kettle available in the rooms, but you might remember it is near to the taverna's and beach, and also a very nice swimming pool which i believe to be the best in the area next too the hotel.
My bro stayed in a hostel in 2003 for a month and he had a very good time, it was cheap and very nice, the guy who runs it was chris at the time, but i am not sure if he has left he prob still be there.
The accomodation at the Alianthos is very nice, and i also had a look at the Alianthos Gardens accomodation as 4 italian mates i met were there, and i think that the rooms in the Garden hotel were alot better than the ones in the beach hotel.
People who have been to Plakias more recently might be able to tell you somewhere better, and you might be able to help another person who is looking for a hotel called the Secret Nest. So if someone tells you where it is look at the articles and tell them.
Wanna chat sometime send me a message
MR P