I'm with you. Before we can argue about whether or not it's a 16th century fake, we first have to decide whether it's even possible for it to be a 16th century fake. From what I have learned of The Shroud, I would have to say 'no'.
Its even worse than that. . . Its not 16th Century, try 14th Century. The Shroud supposedly first appeared in 1350 AD in Lirey, France, not the 1500s. Now we are talking much less realism in art. . . No perspective to speak of. Byzantine tastes, gilded haloes, flat countenances, limned outlines.