We stayed in the Opus Apart Hotel in Kusadasi for 4 days in September. It is located within a resort in the outskirts of Kusadasi. Our double room apartment had a fridge, kitchen, and balcony, and was pretty clean, although the shower wasn't brilliant. Service was very friendly and helpful. The swimming pool is a bit smaller than it looks on the internet, but the terrace and garden next to it are pretty nice. The only problem with this hotel might be the location, a bit far away from the city center and beach (About 45' walking distance). But buses stop very close and very often, so it is not too bad after all. As most modern building resorts, it doesn't have any charm either. Kusadasi itself is not a charmful place, but is very well located if you want to explore the south Agean coast. And so we did with a rented car.
Anyway given the price we payed, I think this place is very good value for money. We definitively enjoyed our stay there.