Just to clarify a bit more:
Bussiness product (EndProtect) uses VPS5, almost everything else uses VPS9 (providing the users wanted to update to newer version of Avast, of course). This DOES NOT mean that the bussiness version is inferior in any way - it just uses data in the older format.
To add to that, we are only talking about the VPS - the program itself (as well as the engine) gets regular updates, no matter the version.