We have been here 3 or 4 times, staying at Ridgetop Retreats twice, and older cottages the other times. Deep Creek is absolutely superb for couples and families who want rest and relaxation or hiking, running, 4WDing. You are an hour from Adelaide yet really feel in the outback. You will see beautiful, varied scenery and wildlife. It is SA at its best.
Ridgetop Retreats are architectural designed and eco friendly. They are very peaceful and have all mod cons. You don't need to bring anything and they are comfortable for 4 people. For the price I agree with the previous review however you are in the bush and sharing with bugs is likely. We've had lots of insects, a big Huntsman, and even a bandicoot share but we see this more as upmarket camping. BBQ facilities are nearby and there are books, games and stereo, but bring your own if you must, There is no TV or internet. So if you expect hotel levels of internet etc you should reconsider.
My only negative... more