Here's what the critics have to say about both performances:
Charles Isherwood, The New York Times: "Mr. Swenson… makes for an unusually dreamboaty Javert. (A beauty contest between hero and villain would be a tough call here.) He musters his inner sinister to snarl and glower with gusto, and his singing has both power and precision. (I liked the way Mr. Swenson emphasized an extra syllable in the word "God" when he sang it at one point, as if the name of the deity naturally stuck in the throat of this vile character.)… The diminutive Cliff Saunders [as Threnadier] capers around like a rabid monkey as he fleeces his customers with irrepressible high spirits, while Keala Settle grimaces and grouses, shooting daggers at her husband as if deciding whether to endure him or put him through the handy meat grinder, the better to keep down the price of sausage."
Joe Dziemianowicz, New York Daily News: "In the all-important role of the dogged cop Javert, Will Swenson's turn can be summed up in one word: clenched. For this show to really work, you need something of an even battle between Javert and Valjean. There's no contest in this "Les Miserables" and that's the miserable part. … Too bad [the directors] push the scheming innkeepers played by Cliff Saunders and Keala Settle to such grotesque, and boring, levels."
Jesse Green, New York magazine (Vulture): "A less-expected delight is Will Swenson. Though his Broadway credits did not suggest the stature and discipline needed for an effective Javert, he offers a highly mannered but convincing interpretation, biting decisively into every musical phrase like a Doberman. … Even that infectious earworm 'Master of the House' is more galumphing than saucy; the better it's performed here quite well by Cliff Saunders and Keala Settle as the grotesque Thérnardiers the heavier it seems. As comic relief it is neither."
Elisabeth Vincentelli, New York Post: "[Swenson] was miscast in his last few outings ('Priscilla, Queen of the Desert,' 'Little Miss Sunshine') but his furrowed-brow intensity and rich vocal tone are perfect here. Like every other great number in a show that kills off half its characters, Javert's big 'Soliloquy' takes place before his dramatic death, and Swenson nails it with fierce angst. … Keala Settle and Cliff Saunders are fantastically funny as the Thénardiers, a pair of nefarious innkeepers. They make the interminable 'Master of the House' a lot less painful than usual."
Marilyn Stasio, Variety: "The fanatical Inspector Javert, who comes alive in Will Swenson's fiercely passionate performance, rages against the fugitive Valjean in 'Stars,' swearing to re-capture him, in the sacred name of the law, if it takes the rest of his life."
Elysa Gardner, USA Today: "Valjean's nemesis, the relentless police inspector Javert, is played by Will Swenson, who conveys the right dark intensity. Like his character, though, Swenson is outmatched; he'll be remembered, at least in this case, as that guy who shared the stage with an extraordinary star [Ramin Karimloo as Valjean]. … Karimloo's unforced majesty can, of course, underscore the mugging around him. There are Cliff Saunders and Keala Settle, providing overzealous comic relief as the conniving Thénardiers, who threaten to reveal Valjean's true identity."
Thom Geier, Entertainment Weekly: "Swenson has never sounded better as the by-the-book Inspector Javert, who has been chasing Valjean for decades, though his performance at times edges toward the bombastic. … And Cliff Saunders and particularly Keala Settle prove hilariously bawdy scene-stealers as the shady, dog-eat-dog Thénardiers. (Watch out for the telltale chamberpot in 'Master of the House.')"
Mark Kennedy, The Associated Press: "Swenson is ramrod straight as Inspector Javert, a man so in control of his emotions that even his speech is hyper-punctuated. Unrelenting and stingy with mercy, Swenson has the slightly unhinged quality of a bloodhound, a performance that explains why he must take desperate measures when doubt creeps in. … With so many scenes veering toward the overwrought, the directors have wisely offered comedic moments a masterful 'Master Of The House' led by the ribald Cliff Saunders and Keala Settle and ones to reflect quietly, as in the simple, ghostly, candlelit Marius-sung 'Empty Chairs at Empty Tables.'"