GDM

Situated between the Southern Expressway and Lonsdale Highway. It's a well established suburb which has some old areas and some newish ones. A lot of the soil in the are is clay and I've heard some of my neighbours talking about the amount of ground movement you can expect each year. House doors and gates will have a different swing on them during summer than they will during winter - some days they just wouldn't shut. But with these hot summers and water restrictions the structures have been feeling it the worst especially the older, more established ones.
Being a clay soil, developing a sustainable garden can be a costly exercise.
Although closer to the coast, I found Trott Park to be warmer than Aberfoyle Park/Happy Valley by at least 3-5 degrees even though our house was well shaded.
The street I lived on was extremely quiet, great neighbours who wave and say hello but aren't too nosey, however, there weren't a lot of young families around that my younger son could play with locally. There are 3 local schools in the area. I can vouch for Shiedow Park Primary as being an excellent, small school with staff who seem to really care about your child's education.
There'd be the occasional latenight party with fireworks - but most of the time it was peacefully quiet with lots of birds and wildlife around to enjoy.
Being at the extreme end of the Reynella Exchange I could not get a decent ADSL connection and my only option was to go with the only provider of Cable - expensive, fast, and without a whole lot of plans/companies to choose from. Which on the one hand is good if you can't decide between plans/companies - but the other bad because there's no competition and they can basically charge what they want. So if reliable Internet is important to you, it will come at a price.
I found the neighbourhood very safe. Not a lot of graffitti that I've noticed, that might have to do with the low numbers of young teenagers in the area. Lots of people get out and walk their dogs around the neighbourhood. The local parks are ok, very dry during summer - but I think you'll find that in most areas.
In summary:
Great quiet safe place to live.
There are lots of walking paths / shortcuts to get around the rabbit-warren of streets if you are on foot i.e. it's actually quicker to walk/ride to the shops from where I lived as if I drove there, the shortest route had me doing a rather large horse-shoe shape route.
It is pleasantly hilly - the rise of the terrain is mildly challenging and provides a great variety for exercise without being too much of difficult choice to walk or take the car.
Internet access is questionable.
If you are buying, it's probably wise to get some sort of detailed structural assessment. The foundations on some houses have faired better than others.