Well since they are a smaller scale the detail on them aren't super real. For me it would lead to a bigger disappointment in representing the characters. I think the BigBoss head sculpt while on the realistic side did a great job of balancing the realism with the in-game model.
Hers an example of a Batman PF which i hate.
On the play arts they, for the most part, look just like Shinkawas artwork. FYI i really don't like Play Arts MGS1 Snakes face, although one of the initial sculpts was very much like the concept art.
P.S im an idiot, when you said PFs i heard busts :S but i stand by what i said lol
I'm pretty certain that Sideshow is creating a Batman bust that's based on Jim Lee's drawings. It actually looks very good. As for Metal Gear Solid, I wouldn't mind other sculptors working something. Just as long as they remain true to Shinkawa's artwork and keep their personal interpretations to a minimum.
