Contra that are the hagiographies: Calvin was the greatest theologian since Augustine. Not only was he brilliant, but he was an excellent stylist. He was a humble man who always fought against having authority thrust on him.
I suggest that both portraits are vastly skewed. As we enter into the 500th anniversary of Calvin's birth, we have an opportunity to re-assess his heritage and legacy. Calvin was a man, a human subject to frailty, foibles, and folly. He would likely be the first to admit that. Calvin would have us look first and foremost to the sovereign God and his majesty. However Calvin was also blessed with great talents and giftedness ... and he would likely rejoice if in our celebration of those talents, we gave thanks to God for the witness of a saint who has gone before.
Volume 5 of BB Warfield's collected works focuses on that great scholar's writings on Calvin and Calvinism. In his biographical sketch of Calvin, he demonstrates that Calvin's early training as a humanist scholar played out in his later works. Calvin, like Erasmus and other minds of the day, marinated their minds in the classic works of Greece and Rome, and this affected his work. He saw himself first and foremost as a "man of letters" - a writer and commentator on the great issues of the day. Hence his voluminous literary output. Whether we look at the Institutes of Christian Religion (Calvin's great systematic theology, which is still highly readable today -- and which focuses on the practicality of a living faith, rather than a purely cerebral faith) or his large corpus of letters, we find Calvin to be a man using his pen and rhetorical gifts to persuade, encourage, challenge, and confront. Warfield demonstrates Calvin's deft use of satire as a rhetorical tool.... showing Calvin to be a man with more humor than is popularly thought.
What we see in Calvin's Institutes is a "positive programme" for Protestantism. The Protestant cause began in criticism, and might have remained there but for Calvin. However in his Institutes, Calvin presents a vision of faith that is illuminated by a supremely majestic God who lays claim to all of creation. Calvin presents all of life as the sphere of service to God. His comprehensive understanding of Christianity as a whole life endeavor was his great contribution to the Protestant cause. The critics focus on the frailty of the man without recognizing the positive life affirming vision for Christian life that he presented.
I hope this year we'll all give Calvin a closer look .... and perhaps take up the task of reading some of his work. The Institutes are a great place to start.... well worth reading and profiting from the insights of this great teacher.
Soli Deo Gloria