Well I can add number of things that are beneficial for as who work or live in Alexander Heights.
Many would like proximity to city (i think is only 14 km) or some might like closeness to all possible amenities (schools, parks, shopping, restaurants, etc). Some might like its proximity to beaches and so on. For me personally is nearness to the McDonald's, Kentucky fried chicken, domino's pizza and other healthy foods that I feed my kids on daily basis ... sorry just joking. I think I got you there.
Alexander Heights is suburb that is situated in the middle of it all. If you are working in the city it is quite close once you get onto Alexander Drive. Hepburn Avenue will take you straight to the beach and Hillary’s Boat harbor and Gnangara road to Swan valley. Freeway is close by as well.
Personally I prefer original part of Alexander Heights around Green Park. This part definitely has more mature trees along the parks and roads that I value a lot.