I would expect the purported positive effects of gaming should be way more pronounced, given the many hours many people play each day. It seems that someone who spends the same time honing a real skill (e.g. programming) would come out way ahead!
Tangentially, speaking of the "costs" of gaming:
A game like Starcraft combines
- a competitive 1 vs 1 mode, forcing a maximum effort each game
- is using a wide range of motoric and cognitive skills, requiring not only quick reactions and multitasking, but also several levels of higher level thinking (analyzing the ongoing game, analyzing build orders and metagame between matches, reading up on things on forums).
To me this seems to lead to a complete exhaustion of the player, instead of giving a challange combined with relaxation and distraction.
I would rather recommend casual games ("let take my mind off work for a few minutes"), 3D shooters (positive stress, excitement, but resting cognitive brain functions) or "thinking games", be it chess, or a civilization style building game (giving a mental challenge that one might have missed in today's work). And avoid a super competitive environment that gives you a negative feedback if you're giving 100% all the time.
Would you agree?