One vote for the current tome covers. They're more mature than previous editions.
One vote against the dungeon-punk look, although I do agree that its only a select few of the illustrations that are guilty of this: Hennet, Nebbin, and all the armor illustrations in the equipment chapter.
The armor illos need to go. These are the core books, not the Dark Sun CS.
And since these are the core books, some of the iconics could stand to look more archtypal- esp. Alhandra, who needs to look more like "St. Joan" and less "mercenary soldier". The only indication that she could possibly be a paladin is her little tat. C'mon, we can do better.
Obviously tastes vary around here- we have the stodgy medieval traditionalists on the left, and the cyberpunk skateboarders on the right. I do realize that dressing everyone in hosen and donning armor ripped straight out of the smithsonian is dull and unrealistic as well, but I would like to see the art design reeled back toward the middle. The FRCS was a good example.