Stayed there in October 2007, was ok, comfortable and clean but as it was end of season didn't find it had many facilities and the staff did not seem that friendly, but that's just my experience at the time.
Tried another 4 star hotel opposite called Didim Beach Resort Hotel in October 2008 and that in comparison seemed to offer more facilities and staff seemed far more relaxed and friendly.
I stayed in Garden of Sun in Feb '07. It was very quiet as it was winter, but have to say, everything clean, food okay etc, we were only there for 4 nights. Pool etc not open then. Last July took a little walk through and it was busy and pool etc in full swing, sorry cannot elaborate further, but all in all my short visit was fine.
Stayed in the GOS in August only lasted 1night, small dirty room, grotty bad smelling bathroom, and miserable staff, would suggest Didim Beach across the road, much better hotal and right on the beach,
surely it cant be that bad,this is a replacement holiday after the hotel i was booked into in cuba for january got blown away in the hurricanes,ive' got 4 daughters to think about 14,13,9,8,could be in a spot of bother then...
We've stayed there twice now, its clean and comfortable, the food is ok, but not what you would expect of a 5 star hotel, our only criticism of this hotel is that because of its size, we found it to be really impersonal. We stay at the Sultan Apts now at the back of the Garden of Sun, its family run, great food, great atmosphere, cant go wrong.
Bit of a difference from The Garden of Sun to the Sultan Apts i would say!!!!!!!!
With having 4 children All inclusive will be so much better money wise, free drinks for the kids free food, beach just across the road, a 15 walk or 5 min dolmus will take you into the Centre of Altinkum, GS has tennis courts and footie pitch. If you liked marmaris not sure if you would like Altinkum???
Or try the Didim Beach which is across the road from The GS
Ive stayed at the GOS and the rooms were clean and changed regularly, they are very friendly and I think there will be loads for the children to do. Turkey don't do all inclusive like other countries, you only get local drinks but the food is plentiful. i think it now has its own section of the beach by the marina bar. Pool is lovely and lively. Altinkum has good nightlife for all of you, so go for it. A holiday is what you make of it.