Regarding the fact that children who spend a lot time playing video games are smarter than others, I very much doubt it, but the fact that they learn quickly and understand some things better than adults is a fact
Video games are proven to improve a variety of skills. Action games dependent on quick reactions and planning help hand-eye coordination and vision. Strategy games offer a variety of other benefits (planning, imagination, sometimes math).
I grew up playing games a lot and I don't regret it.