I've looked through the recent canon novels Tarkin and Lords of the Sith, which should provide us with a view of the Empire as seen by high-ranking Imperials who might know something about the Imperial economy and the state of various Imperial systems.
The Emperor himself thinks life for ordinary citizens isn't great, but not much different than the Republic:
Out there were people who wished him dead, others who envied his station, and still others who wished merely to be close enough to him to sate themselves on the crumbs he brushed aside. The thought of it was almost enough to transform his disgust to sadness for the plight of the ordinary. But the wretched practices of the Republic endured: corruption, decadence, the lust for prestige. A penthouse in an elite building, a position that opened doors anywhere in the Core, collections of priceless art, the finest foods, the most able servants … He never had need for any of it, even when a senator, even when Supreme Chancellor, and had subscribed to luxury only to satisfy juvenile fantasies and, of course, because it was expected of him.
Tarkin, p. 242
Most Imperial systems didn't complain about the transition from Republic to Empire, although there was some rebellion (just as there was with the Republic):
Since the consolidation of the Republic into the new Galactic Empire, pockets of chaos had appeared here and there. Most of the former Republic accepted the Empire without complaint, but there were many bands of resistance fighters and Separatist remnants lurking around the galaxy.
Lords of the Sith, p. 31
The Empire was expanding, indicating an adequate economy:
Constructed soon after the end of the war atop monads that had once made up the Republic’s strategic center, Naval Intelligence was a nexus for gathering and analyzing transmissions that poured in from across the ecumenopolis and from all sectors of the expanding Empire.
...
As his Empire swelled, bringing more and more of the outer systems into its fold, so too would his power unfurl, until every being in the galaxy was held captive in his dark embrace.
Tarkin, p. 152, 242
And the Empire is in firm control of the galaxy:
Eight years after the Clone Wars ravaged the galaxy, the Republic is no more and the Empire is ascendant. The man who rules as Emperor is secretly a Sith Lord, and with his powerful apprentice, Darth Vader, and all the resources of his vast Imperial war machine, he has placed the galaxy solidly under his heel.
Lords of the Sith, p. 4
Former Separatist worlds did not fare well (partly as a deliberate punishment by the Empire). For example, the Imperial ambassador to Murkhana indicates that life on the planet there isn't good (although Coruscant, the Imperial capital, is doing well):
[Tarkin] wasn’t surprised to see that most of the city’s charred, devastated buildings had yet to be demolished. Facing sanctions, the local government had not been able to grow the economy, and the substantially reduced population had been forced to rely on black marketeers for goods and resources.
...
“Maybe you two [Tarkin and Vader] haven’t noticed, but Murkhana isn’t Coruscant. The population here hates me. I sometimes think Murkhana hates me. I’m held responsible for every Imperial tax increase and every minor change to the legal system.
Tarkin, p. 107, 118
(Imperial tax increases aren't surprising -- someone has to pay for those Death Stars.)
Other worlds, such as Ryloth, were exploited. This improved the Imperial economy in some sense and improved the lives of those who benefited from the exploitation, though of course it made life worse for the exploited and encouraged rebellion from them. Some of the exploited people could better their lives by collaborating with the Empire:
The sight of Imperial ships sometimes upset the natives. So he left the day-to-day policing of the city to a Twi’lek security force, made up of Twi’leks co-opted by better living conditions and pay to enforce Imperial rule against their own people.
Lords of the Sith, p. 43
This description of Ryloth actually sounds quite similar to the Nazi occupation of Europe during World War II.
Summary
Compared to the Republic, the Empire is characterized as more orderly (due to a more authoritative government and military) with society more stratified due to increased use of slavery. The Imperial economy appears to be about the same as the Republic, and corruption has endured since the era of the Republic. There are pockets of rebellion against the Empire, but the Republic was torn apart by separatists, too (granted, with some help from the Sith).
Overall, Palpatine was an effective ruler in the sense that the economy remained stable, the Empire was able to expand, and most systems accepted Imperial rule without a fight. Palpatine was not effective in the sense that he had to use slavery and tax increases to fund the Empire, but he had no problem with such practices and did not care to avoid them anyway.
