The New Republic just degenerated into what the Old Republic was, so ultimately, the Empire was probably better for average citizens.

In fact, that's usually the way it is with empires. They crush dissent ruthlessly, but they also facilitate the trade of ideas and goods, suppress nationalism and endure for a long, long time.

Empires, historically, last much longer than republics. The Persian Empire outlasted Athenian democracy and the Roman Empire lasted for about twice as long as the Roman Republic (or, if you count Byzantium, about four or five times as long). The Russian Empire survived for almost 400 years. Empires even tend to survive revolutions (Russia did, Rome did, Persia did) and often, invasions (once again, Russia showed this).

Empires fall when they show weakness. If Palpatine had just used the Death Star on Tatooine once the plans were determined to be there, he would have wiped out Kenobi and Skywalker as well as those two meddlesome droids, Han Solo and Chewbacca (not to mention wiping out Hutt criminal syndicates). Without them, Leia would have been executed in the Death Star and the rebellion would have failed.