If the grass patch fits your needs, go ahead and use it, but I agree with Rutra, I think it looks absolutely awful, lol!
If you want to go for reall grass everywhere, be aware that you will need many instances, probably in the millions range, and this will take a lot of time to render.
Vue7 offers to dynamically populate ecosystems, so they only show in the camera's fov, which would save resources.
For longer shots, fake it! It will be a lot faster, and if the shots are animated, won't need as much flicker reduction. I found that the new Grass variation material looks absolutely stunning, provided you add some bump to it based on the colour production function.