I did a 2 year stint there for a work posting a tickle over 10 years ago. The first 12 months of that we lived in Yeppoon and commuted to Rocky each day for work. I really enjoyed Yeppoon as it was on the water, and close to some great weekend escapes (Byfield, Keppel, fishing, beach, resorts etc). I found the climate to be a bit more comfortable in Yeppoon than Rocky. The daily commute to Rocky was about 40km ant took about half an hour.
The second 12 months we lived in Parkhurst on the North side of Rocky. It is a suburb of mostly 1 acre blocks and was a pleasant place to live. I found it hotter in summer, and colder in winter (compared to Yeppoon), and the commute from there to town was about 15 to 20 minutes. I've lived in Brisbane, Townsville, Cairns, Rockhampton & Mackay for mostly 2 year stints while in my old job, and In my opinion Rocky was no worse of a place to live than any where else from a crime point of view, just do your research and chose the right area to live. From a lifestyle point of view, I found Rocky to be a bit isolated. Sure, there is some good stuff around the area, but not as much as other bigger places.
Just my 2c. I didn't mind it as a place to live and enjoyed my time there, but it's been 0ver 10 years since we left, so probably cant offer good advice about what it's like now.
Try some of the real estate websites and look at the house / rental market. That should give an indication of the type of homes in different suburbs, and the prices should indicate the type of demographic (dearer prices suggest more affluent area, cheaper prices suggest the area my be a little rougher).