G'day
Here I am 35+. My reaction is 'positive', but only because I have low standards for interior art in RPG products.
In my opinion most of the art in 3e is technically competent, which makes it outstanding by RPG standards. Characters' proportions are correct, moulding and shading give a real impression of solidity. Most of it looks at least okay, and a good bit of it is really quite decorative.
However, I do have some issues with the clothes, which look like nothing that anybody ever wore except on a catwalk, and like nothing that could be made in a society with quasi-mediaeval technology, or that anyone except a fetishist would wear if they had a choice.
Also, I am rather disappointed to find that the illustrations are rather bad at illustrating anything. Most of the armour on PHB 106-107 looks nothing like the armour types it is supposed to illustrate. Moreover, most of it looks incredibly heavy and almost totally impractical. I have similar complaints about many of the weapons on PHB 102-103. Even forgiving the artist for ridiculous weapons such as the double axe, gnome hooked hammer, urgrosh, spiked chain, two-bladed sword, and dire flail; the greataxe, halberd, warhammer, falchion, and rapier are all appalling. It is plain that the artist had no idea and did no research. Compare with some of Angus MacBride's work for Osprey Books ('Men at Arms" series, "Elite Series") and Iron Crown (much of their MERP stuff): historical weapons and armour look great, this scrapyard punk look is not even a visual improvement.
The general observation that the art is better in the decorations than in the illustrations applies with sad force in the MM. There, where good illustrations are most sorely wanted, too many of the illustrations look like nothing in particular, and the standard of technical competence is lower.
My unhappy observation is that most publishing people think of interior art as decoration rather than illustration, and that even good examples (such as the PHB and DMG) is designed much more as decoration.
A picture is worth a thousand words. It is a great shame to waste a thousand words saying nothing but "Lidda has a buckle fetish".
Regards,
Agback