I don't think IW versions are definitive at all, certainly not for me anyway. I'm glad I don't particularly like this IM armor, I won't feel bad passing on it. Frankly the only figure I might be interested in is Teen Groot with sullen facial expression. But for those who like these figures, that's great - keep Hot Toys open so maybe they'll make some figures I'll be interested in down the road. When I think of Iron man, I think of the Mark IV, VII, and I think my personal favorite might be the Mark 45 - it just has an aesthetic between the more more classic look and the streamlined look which I find appealing personally. When I think of Thor (even all the comic book covers I've seen, and I don't follow him real close so I expect he's had a few different looks) the most definitive look is long hair, no eye patch, cape, bare arms, but the head sculpt does most resemble Hemsworth on this new Thor figure. Rocket, well he doesn't look that different. Doubt any of the other Guardians (besides Groot) will look too different, but maybe we'll finally get a Nebula... maybe. Captain America surely doesn't have a very definitive look, I'm thinking more Avengers 2 and Civil War were the best figures of him. He doesn't even have any red, white or blue in this one, he's got more of a Teen Groot vibe than a RW&B Boyscout vibe going. And Black Widow... blonde? I mean, I really don't care, but if we're going for an iconic look, I don't think blonde is it.
Especially since DC is sinking into the Abyss in the film industry.. what’s left SW..not with Disney’s direction 
