Here is a 15 year old article (not a big deal really when you realize that the subject matter is over 500 years old) about Verrocchio's Christ and St. Thomas. Kimmelman is a good critic and writer and I think he makes important points here - especially calling out Vasari for his belittling of Verrocchio, which does not stand the test of time:
If it were by Michelangelo, there would no doubt be lines stretching all the way from the museum's lobby to the Lehman wing, where "Christ and St. Thomas" is on view. But Verrocchio's reputation was long ago wounded by, who else, a critic: Giorgio Vasari, writing in 1550, almost three-quarters of a century after the unveiling of "Christ and St. Thomas," described Verrocchio's art as "hard and crude, since it was the product of unremitting study rather than of any natural gift or facility." Vasari's opinion has echoed through time so that now Verrocchio may be better known as the teacher of his studio assistant, Leonardo da Vinci, than for his own prodigious achievements.