Their opinions are so much trivia at this point since "You're Welcome America" is pretty much sold out, but it's still nice to see that, e.g., Ben Brantley likes the show even though Ferrell-as-Bush doesn't think much of the New York Times.
Still, for the record, below are links to reviews from some leading press outlets. (I'd say David Rooney of Variety pretty much nailed it.)
New York Times
"The Comedy of Ineptitude, Political Division"
by Ben Brantley
"You're Welcome America. A Final Night with George W. Bush"
by David Rooney
"Doin' a Heck of a Job, Willie: Ferrell's Frat-Boy Bush Freshens Broadway Show"
by Peter Marks
"Will Ferrell relives 8 years of George W. Bush"
by Michael Kuchwara
New York Daily News
"Mission Accomplished! Will Ferrell is stupid good as former president George W. Bush on Broadway"
by Joe Dziemianowicz
New York Post
"BY GEORGE, IT'S A FERRELL OF LAUGHS"
by Frank Scheck
"Ferrell's Bush Lap-Dances With Condi, Digs War"
by Jeremy Gerard
Ben Bass and Beyond
by some knucklehead