Just adding an update to this...
The Ekies Manor is lovely!!! Soooo relaxing. The private beach is sheltered and clean, the pool is great, rooms are wonderful and food is yumola! Prices of course reflect this - it's not cheap. We went as a treat when I was pg with twins as we knew it'd be a while before we had another holiday abroad. A very enjoyable fortnight was had and I only wish we could go again...
The resort of Vouvourou is very quiet - only a handful of tavernas, serving gorgeous local dishes. The fish is superb.
We hired a car and explored the Sithonian and Kassandran prongs of Halkidiki, as well as visiting Thessaloniki twice. Great city and easily accessible. Also took a boat ride along Athos peninsula to see the Holy Mountain and the monasteries - amazing!
If you want a relaxing holiday in a beautiful place, then Halkidiki is for you. The sea is the cleanest I've seen anywhere in the Med/Agean, and the place isn't packed with beer monsters, even though the area gets lots of visitors in the summer.
Definitely recommend it