From what I am reading of Calvin's own work, it is obvious to me that he carefully thought through all options when examining a passage of Scripture. He showed a very comprehensive knowledge of Hebrew and Greek and discusses the different shades of meaning of the different words. He discusses what possible interpretations of a passage are viable, what he thinks is far fetched, and what he prefers. He doesn't appear to show prejudice for any personal dogmatic stance, but considers all the shades of meaning in a passage and comes to his own conclusions. Often he might have a slight disagreement about a possible meaning but he says that he is not going to be contentious about it if others want to stick to it.
So, if someone is so well versed in his knowledge of Old and New Testament Scripture, and has a comprehensive knowledge of Greek and Hebrew, then his writing is worth serious and careful consideration.