First up is the New York Post's Elizabeth Vincentelli, who feels that the cast change "reveals that the play is strong enough to leave actors interpretative wriggle room," even as she admits that, "at first glance, hiring the stately, composed, African-American Phylicia Rashad to play the pill-popping, spiteful matriarch of a white family smacks of stunt casting." She admires how Rashad avoids imitating Deanna Dunagen's "speed-freak" take on the role, instead revealing more layers of vulnerability and pathos while "stopping short of making Violet sympathetic". She winds up giving the show 3.5 out of 4 stars.
Also in the plus camp is Theatremania's Dan Balcalzo who says that Rashad "more than rises to the challenge of this demanding role, turning in a complex and riveting performance from start to finish." Discussing her in context with her predecessors, Balcalzo writes:
Deanna Dunagan, who won a Tony Award for her portrayal, was a high-octane spitfire, barreling down the stairs of set designer Todd Rosenthal's tri-level set. Rashad takes the steps much slower, although she dances just as manically to the Eric Clapton record playing on the stereo. Estelle Parsons -- who succeeded Dunagan and will be starring in the national tour that launches next month -- projected a surface sweetness that made the bilious remarks that came out of her mouth even more shocking. But there are no soft edges to Rashad's Violet. Instead, she exudes a hardness chiseled into her features from years of painful experiences, including the claw hammer story that Violet memorably relates in a pivotal Act Two dinner scene.
David Rooney at Variety writes "the show remains crackling entertainment, an edge-of-the-seat roller-coaster ride through the ultimate in family dysfunction that has lost none of its humor or horror." As for Rashad, she makes the role her own by being "considerably more stoned, vacant-eyed and slack-jawed as she weaves around designer Todd Rosenthal's American Gothic doll's house between perplexing rants and lacerating attacks. But she also reveals more of the wounded little girl beneath the surface of this damaged, damaging woman." He also feels the "nontraditional" casting makes the play more theatrical by requiring a greater suspension of disbelief on the part of the audience.
Meanwhile, one of our favorite revieweres, David Barbour writes in Lighting and Sound America that the play has "lost none of its rattlesnake vitality". About i'ts new monster-in-residence, Barbour proclaims: "Rashad has captured [violet] in every hair-curling detail. Check out the lady's eyes -- one minute they're flashing flirtatiously at the nearest male; a second later, they're honing in on her next victim, getting ready for the kill."
Further heaping on the love is Time Out New York's David Cote, who writes that "Rashad is an excellent—if unconventional—addition to the half-replacement cast of Steppenwolf’s hit drama, breathing new fiery life into the juicy role...a rare case in which a bold-faced casting choice pays off dramatically." As for the rest of the production, he has nothing but high praise, giving the affair five-out-of-six stars. (It should also be noted that Time Out was amongst the more vocal doubters of the choice to cast Rashad, for reasons explained by Helen Shaw on their blog here.)
Lone dissenter Matthew Murray (of TalkinBroadway) feels that the show in general has lost some of its angry caustic spark:
"What’s missing these days isn’t so much energy or precision as the clenching, caustic rage that once made the Oklahoman Westons so deliciously brutal. Letts’s play, for its uncommon size and scope.. has always been barely half a step removed from hand-wringing sitcom triumphalism. This gloriously inelegant rant against the oppression of and within a prototypical Red State thrives on smartly startling outrages - things like addiction, adultery, pedophilia, and of course incest - to fuel its scathing indictment of the Midwest’s corrosivity."
Some of this blame Murray heaps at Rashad's feet for occasionally going for laughs and softening Violet's edges.
So there you have it, folks. A general consensus in favor of the new actress and interpretation, with one quite vocal outlier.