Simply mindblowing.
The one thing that this stadium photo has achieved is the sense of massiveness.U really can feel that the stadium is huge and big.not like crappy EA stadia, where it feels like a backyard.
Now, looking at it in a little bit more, there are some aspects that can be improved:
1.The grass can't shine that much.also, note the reflectivity of grass.there is a gradient from one part of stadia to another.and that's unrealistic for grass.
grass is a diffusion kind of texture.can't produce gradience like that.
also, like Muhammad Saad pointed out, there needs to be a bit of uneveness.
2.there are also a couple of super minor things but they hardly need attention.