What I take from the scholarship (e.g. Chris Wickham's _The Inheritance of Rome_) is less "the fall of Rome wasn't that bad" as "various things changed in various places, but there wasn't a single event where everything changed" and "the `barbarians' who supposedly took over Rome were virtually indistinguishable from the `Romans` who preceded them".

And there were surprising details, such as that after the Arabic conquest of many areas, the conquerors pretty much kept relying on Roman era tax rolls and local organization.