We went to Turunc in July a couple of years ago and it wasn't too busy then, there are lots of nice little restaurants and a couple of bars but no loud music or clubs. Our children are younger than yours but we had a really nice time.

The transfer was quite long and we had to drive over a moutain with really winding roads to get there, wich is the only thing that would put me off from going back. If you want to go into Icmeler or Marmaris for the day though you can get a water taxi rather than doing the mountain route.

I don't know what prices are like in Iceler but we did find it just a little more expensive than where we normally go around Bodrum. We took a little lira to start with then changed sterling and got cash from the ATMs.

Many families who like the sort of holiday you described go regularly to Turunc.
It is about another 1/2 hour on from Icmeler, takes about 1 1/2 hours to 2 hours by private transfer from the airport, depending on how fast the driver is. As Kedi said you have to go over the mountain road from Icmeler, so although its not that far mileage wise, that part of the journey is slower. We think one of the joys of the journey are the fantastic views, the view when you first see Turunc Bay is spectacular!
It is extremely easy to change your sterling there, and you can also use sterling in many places. The exchange rate is usually a lot better than in the UK. We usually take about £50 in Turkish Lira, and the rest in sterling, and keep it in the safe, and change smallish amounts as and when we need it. There are travel agents and shops in the main street, who will change your money very easily for the same rate you would get in a bank. Prices for food and drink are usually a little higher than Icmeler.
I don't know anyone who has stayed at the Sen, but I believe the food is good and they have regular barbecues. It is on the main road, going out of Turunc, about 3-4 minutes from the main street and beach. Our favourite restaurant is next-door - Bonjuks where they do the most delicious oven baked lamb.
There are walks around Turunc, you can walk to the next bay Amos, and further on to Kumlubuk. We have walked on the donkey track over the mountain - its a lovely walk with fantastic views. Don't think we would do it in August though - its much too hot!

Car hire is easy to arrange there, and driving around the Bozburun peninsula is a great day out. It is also possible to drive to Datca, which is a lovely drive to a really nice traditional Turkish town, with very few English tourists.
Whatever you choose, have a great holiday!

Thank you for your replies - they have been most helpful.