I won't use aluminum adapters fittings in brakes or PS systems, only steel. I'm sure that aluminum adapters will take the operating pressure, but that is only a small part of the whole picture that these two systems operate within.
Using adapters rather than unique hose ends means that future changes and field repairs are easier. Special hose ends aren't always easy to find, but an AN hose end is, and so are most adapter fittings.