AS3 is an event based language, user interaction is caught and dispatched via events and there's nothing that can be done to stop that. Using signals is only adding a second system on top of the one you can't get rid of. Signals work well on other programming language either not event based or flexible enough to allow another system to take priority. This is not the case in AS3 and you can come up with a thousand different event systems if you want, you'll still have the AS3 event system on top of everything. no way around it. Besides many people like signals because that saves them the trouble of writing custom event classes but in a company environment custom event classes means code highlighting, code completion, signals mean use constants at best.
Concerning a test request, it's irrelevant to compare a private framework to a public one especially when this framework is no longer in use anyway. But a public framework has the inconvenience of having to fit as many cases as possible, a private doesn't have that restriction and for that reason is likely to be more efficient.