Just for example I have dumped some pics up to show the comparison between KR Legacy Art view and KR default view. (legacy on left) Have put in thumbnails as the graphics are quite large, but needed them that way so you can see the difference easier.
1. fully zoomed out shot of one of my castle roofs, the kr legacy view to me is so much more 'crisp' to view, but I think the wagon, palms, fountains, fountain of life, gnarled staffs on the pergola, the horse and cart on the corner, and the barrel graphics are heaps better in the default view. Also note how the 'grass' retains the KR default look, which is imo way better than the flat green mass of 2d grass.
2. zoomed in section of same roof. I think the main difference is although the KR default graphics stand alone are 'better' per item, the fact they tend to have a softening to them with a less defined 'edge' means when in mass they tend to give the perception of 'blurring' which gets hard on the eyes after a while. The 'crispness' of the graphics tend to disappear, especially in heavily landscaped areas.
3. Section inside another castle showing more detailed 'item' type stuff. In this one I am not sure which view I prefer. The legacy or the default. However in this case I did the actual deco in the 'KR default' which is I think why the items appear to be correctly placed rather than deco'd in 2d or KR legacy, and then just viewed in default. The nice thing about KR Legacy is the polar bears retain the KR default graphics, personally I love all the KR monster/pet graphics, even tho some of them take a bit of getting used to when you first see them.
It is all a matter of preference, I know a lot of people will stick with 2d til the end of time lol, personally I have found the mix and match approach pretty good as it has taken away some of the boredom and lets you look at things a little differently, nothing can beat the UI on KR tho, once you get used to it going back to 2d is hopeless lol.