What Lombra said. There are two main reasons to use AceEvent-3.0:
- Hooking two or more events to the same function (function, handler, and callback all basically mean the same thing)
- Passing an additional argument to the function that the events do not pass
There are also two main reasons to not use AceEvent-3.0:
- As Lombra showed, unless you need the above functionality, it brings nothing but overhead
- It does not support RegisterUnitEvent, and can conflict if not processed correctly
If you are on the fence about whether or not to use AceEvent, then I suggest not to use it.