Kelvin is the master of textures and I am a texture whore literally. 
By the way I played Metro Last Light for the entire night (today) and wow...I never seen such quality textures in my life in a game...even better than The Witcher 2 or Battlefield 3.
A sample of one of those textures in the floor that called my attention just because it looked so real.
And the full gallery with 100+ pictures until half of the game...I´ll finish it later tonight.
http://imgur.com/a/gVlDg#0
This is probably the best looking game ever made to date.
BUT Outerra is my favourite Graphics Engine.
Thanks for the compliment. This looks very nice also.
I can see this being a very "tiled" texture over a spanned distance and the amount of work to try and get it to not tile on a larger landscape would surely reduce the quality significantly.
IMHO the primary issue with any game textures like this is repetition. Reducing the span of a texture or finding a transitional method between multiple textures would offer less opportunity for the eye to detect the tiling effect, although this effect can be very noticeable in even smaller areas. processing or high passing a texture too much to reduce the tiling can also ruin the texture and you can then loose the 3d effect. Also, not all textures will work so a fairly time consuming effort can be put on a single texture to get it looking perfect.
The difference for OT is that most games out there do not have the problem of having to span textures large distances. There are many things that break the texture i.e static ground models, foliage, etc... so there's a sweet spot to be found with the textures in terms of quality. Some textures that we know may tile (like in your screenshot) will be ok to use in a small area because the texture doesn't have the chance to repeat enough to notice.
Two other significant factors to consider is object (i.e stone shadows) lighting in the image and the distance from the eye perspective to the actual texture objects. I never realised how much is involved when putting a texture inside a game, but the end result can be very pleasing indeed.
K.
