Hi,
You can use Airwave if all sites have network (IP) connection to the HQ where Airwave can manage all the VC controllers as separated instances.
You can use Aruba Central to manage all the sites, separated in groups inside Central, were each group may have different configurations.
The benefit of using central is that you can extend some features like captive portal and analytics by adding feature licenses.
This could provide, for example, a self registering captive for guest users and even information about users and presence data.
I believe that Central requires less effort to be running and improves some features that might be useful.
regard,