There's no doubting that it ehlps to have awesome artists too.

It does still look good, but it's really still relying on old techniques.
Quote: "they repeat quite obviously, and there's a limit of 4 textures... I mean... we can both probably understand that, if they're using vertex colouring for texture assignment then that makes perfect sense... but its also weak as hell, and ourselves we wouldn't settle for that. I'd guess that its a limit for the whole game, except we can't assign different textures to different terrain mesh chunks."
Not sure I follow here - my terrain uses an atlas so you can have as many textures as you wanted - I settled for 16. You can also easily assign a new texture set to each chunk if you so wished - when I fully build my landscape example it will have different zones with different texture sets.
As an aside, I had a to do outstanding to improve my grass, which I have done. This image shows a slight modification, but now grass is drawn using an atlas. Here I have 8 distinct types, but I could have 100 if I so woshed, and the random chance of any one type is controllable. So in the realworld I could assign a grass image to each step of green in the color channel and manually, accurately place the type of grass for up to 256 different images, and if you wanted to be SUPER EXTREME you could then do that for each channel. I've settled for random mixing based on % chances, so will probably build somehting in that allows "chance zones" to be drawn....so types X,Y and Z can be set to be more likely near water for example.
The shading needs work but it looks more natural and "wild" compared to the single image version.
Again.....all grass is one single mesh so it's really quite fast to render.