Lifespan
In UK vet records the Australian Shepherd lives longer: a median of 13.7 years, against 12 for the Belgian Malinois.
Grooming
The Australian Shepherd needs more grooming, brushing a few times a week, where the Belgian Malinois needs a brush once a week.
Temperament
They differ most on affection (Australian Shepherd: affectionate on its own terms; Belgian Malinois: likes its own space) and on sensitivity (Australian Shepherd: average; Belgian Malinois: needs a calm, predictable home).
Alike
They are much the same size as adults, about 24 kg (52 lb) for the Australian Shepherd and 25 kg (55 lb) for the Belgian Malinois.
Alike
Both are rated the same on independence: keen to work with you.