With the knowledge about society that I have as a modern person, I would have supported whichever side offered the speediest path to reform; the senatorial system was collapsing, the Republic was descending into a series of civil wars that would ultimately have destroyed it. The empire managed to delay this by a few hundred years, but eventually it went back to civil wars which were again close to tearing it apart. Various reforms (such as sharing the Caesar and Augustus offices) again managed to make ends meet for a time, and christianity may have been a stabilising force in the last years of the (western) empire. But once the pressure from outside increased against this rickety construction, it finally collapsed.

What amazes me is that it took so many centuries for Rome to actually disintegrate, since instability set in as early as the second century BC (just ask the Gracchus brothers).