Shedd's unbalanced nature doesn't really concern me, actually. Every systematician has to decide which issues are more important in his time and place than others. He is also a good writer. However, he has some quirks. He is not what I would call a vanilla Presbyterian. He holds to traducianism, three parts to the human person, and most concerningly, some of his Trinitarian formulations are suspect.
He does the same thing in his History of Doctrine. It looks like he is reinterpreting some passages of Augustine around Coleridge's idealism, and I never thought that was a great idea.