Realism. Good proportions are a must. I don't know about everyone else here but I want to feel like I'm in the 40k universe, not like I'm playing some 'cartoony' game. I want it to look as realist as they can make it look (obviously without compromising performance) because I was to feel as if I were there.

The art should accurately reflect the dark and brutal nature of the 40k universe.

not the same proportion(i tink the TT have heroic proportion) but the same "feeling" of the miniature, armor and weapon don't need to have realistic detail.

Miniatures' proportions are dictated by the terms of durability. Realistic heads and hands will just break off.
3D models can not break, so no need in following TT cartoon proportions

I disagree, I don't view the proportion of thier hands and heads as cartoon or unrealistic, considering thier overall size and other mutations it doesn't seem unreasonable to have larger stronger hands better able to hold large weapons and lift heavy items, and larger skulls with thicker bones and larger brains.

I'd personally like a dark and but somewhat stylised approach to the art. I don't think ultra realism really fits with 40k tbh, but I do think there's a place where they meet, would be perfect.

I too wold definitely like to see the GRIMDARK, especially on the Chaos side.
So don´t shy away from the gruesome details!

It definitely should not be different shades of brown. It needs to be Grimdark but with a bit of stylization, gritty realism just doesn't fit in a game with the backstory of 40k.

Yeah.. this is not true at all. I've got models that are far slimmer.. and GW even puts out many that are extremely thin. Real-world military models as well as many figures form other companies are scaled more realistically and don't have any more or less problems with this. Guns are another story...

Gore is definitely a must. It's not Warhammer without proper gore...and lots of it.

/K

Personally, I'd prefer something darker, grittier and dirtier...not to mention bloodier.

Those overly saturated in-your-face vivid colors make my eyes hurt and it's not what at least I associate with the Warhammer universe.

/K