I just wanted to mention that I prefer your previous WIP over Feron's edit and over your current WIP, as I find them quite hard to read and I think they need some AA or something, and I prefer the color of your previous WIP. Hmm, they don't look more realistic to me either :\. I most prefer Helm's edit out of the lot, as it's very clear and has nice variation in stones, which I think makes really good use of the colors.
Something worth noting, is that after upgrading to an LCD monitor, pixels seem much clearer/distinct and it's much easier to see problems with AA. So if you are using a CRT monitor then this might be something to think about.
Anyhows that's about it. I think things are looking quite nice otherwise,
I just wanted to add that maybe my thoughts would change if I saw the tiles together with everything else, like in a mockup, as I find it hard to be sure of things without seeing everything together :\.