Rafa is one of only a handful of managers to ever break the Barcelona/Real Madrid hegemony in his native Spain. His two Liga titles and UEFA Cup win with Valencia established him as one of the game's most capable coaches, something that was reconfirmed by that remarkable Champions League win with Liverpool in 2005 and to a lesser extent his UEFA Cup win with Chelsea earlier this year.
Nevertheless, doubts about his real worth remain in some quarters.
Benitez remains a cult hero in much of Liverpool, but he is roundly derided in Milan thanks to his difficult time at Inter.
And thanks to his confrontational attitude during his time at Anfield, there were some in London still dead against the Spaniard even after he'd steadied the Chelsea ship in the choppiest of waters, secured Champions League football for next term and even added another European title to boot.
So is this the right man to take Napoli to the next level?
It's hard to say. Walter Mazzarri is a tough act to follow. The Tuscan coach, now at Inter, built a formidable side in Naples and had them playing football that was often the toast of Europe. And this season they finished second, so only going one better and winning a Scudetto could count as real improvement.
That said, Mazzarri's Napoli didn't win as much as some believe they were capable of. And after four years of trying, both the coach and the club seemed to agree that it was time for a change. Which is just what they'll get with Benitez.
The most obvious change will be how the squad lines up on the pitch. Mazzarri's various incarnations of the 3-5-2 formation is not likely to suit Benitez, who favours a more robust 4-5-1.
There are obvious pros and cons to this alteration. Some will see the swap as the end of Napoli's entertaining brand of football, while others will note that the change should see an improvement in an area that's held the Partenopei back: their defence.
Mazzarri's Napoli conceded 50 percent more goals than the eventual Serie A champions Juventus this term, but for the most part only lost games by a one-goal margin.
Looked at a different way, their goal difference was just minus-8 for their six losses this campaign. That's an area obviously ripe for improvement and even marginal gains in the defence department would close the nine-point gap that separated Napoli and Juve this time around.
A sturdier back line shouldn't hamper their efforts going forward too much either, because according to the Lega Serie A (here, in Italian) a massive 44 percent of the goals they conceded came right before the end of each half. That suggests that the problems are more mental or physical as the players tire and the system is broken down by their opponents. Benitez is known for always being defensively prepared, so his Napoli side should be more robust.
There's another aspect to Benitez's appointment that signals change, too, though it's less easy to quantify. By signing Rafa, Napoli have secured one of the continent's most high-profile managers.
Benitez comes with an impressive CV. Few have been more successful in Europe and he'd been linked to the Real Madrid job following Jose Mourinho's departure. His signature is a signal of intent from Aurelio De Laurentiis, the successful film producer who knows better than most that a big name is good box office.
The fact that Benitez sees a future for himself in Naples shows how serious De Laurentiis takes Napoli's title credentials—and hints that he's willing to spend to prove it.
Napoli have had a good run for a side outside of Italy's traditional northern axis of power, but they're at a crossroads now. They either go all in and see how far they can get or settle into the role of a mid-table, selling club and hope that every few years a young crop of talent leads to some small success.
Getting Rafa on the bench says that De Laurentiis favours the former. Rafa's biggest bone of contention throughout his career has always been signings, and there's no way he's gone to Naples without assurances on the competitiveness of his squad.
He clashed with Jesus Pitarch at Valencia and with George Gillett and Tom Hicks at Liverpool. His time at the former certainly saw plenty of movement in the transfer market, but as the pro-Rafa camp is always quick to point out, the famous "net spend" was actually quite modest for six seasons at a major EPL club (here, via the Telegraph).
He almost immediately came into conflict with Massimo Moratti at Inter over the president's unwillingness to spend, too. Benitez believed that Mourinho's incredible treble run the previous season had papered over the cracks at the San Siro and wanted to rebuild. Three years on, even the most fervent Interista would now probably concede that he was right.
He'll find no such squabbles in Naples. De Laurentiis wants a championship team, and by doing all he can to hang on to Edinson Cavani, he's proving it. The speculation surrounding Napoli's star player is one of the biggest transfer stories this summer, but the Azzurri are holding fast to their man—at least for now.
Is Rafa the right man for the Napoli job?
Mazzarri will be back to Naples with Moratti's chequebook, but that might suit Benitez. The shift from a three-man back line is going to require some new faces and some spaces on the squad sheet. Some quick sales to Inter can get things moving.
This will be an interesting year in Naples. The triumphant Juventus and a resurgent AC Milan look like the early title favourites, but there's a lot happening at Inter and Roma as well, so title success certainly won't come easy for the new boss.
And as mentioned earlier, anything less than another second-place finish in the league might be taken for a step backward by the Napoli faithful. Or it might be seen as the zenith of the Mazzarri era, one marked by development and consolidation more than success.
For all his success at the San Paolo, there was the feeling that Mazzarri's time had run its course. A fine coach, certainly, but perhaps one in need of a change. His Napoli were roundly beaten by Juve in the end, and unlikely to improve next term.
He also lacked continental experience and for a club like Napoli, the ability to shepherd the team to the late stages of European competition would be of great financial benefit.
Benitez is an old hand on the European stage, and a good Champions League run with a top-three league finish and perhaps some cup glory would signal an advance on last year's runner-up spot. A short-term negative, perhaps, but also a step forward into a new age of genuine potential.
What do you think? Let me know on Twitter, @ColliOBrien.