Mike, this is as you note, a complex and highly volatile area for anyone wishing to get educational value from games technology. However, I would offer this overarching observation.
"...games playing as currently practised is fundamentally anti-educational because education can be defined as precisely that step change a culture takes when it shifts from informal games playing within families or peers to construct a formal system specifically designed to pass on inherited cultural values and knowledge. This is in fact why games are widely viewed and experienced as non-educational by children and teachers alike — because atavistically and culturally, they are."
From a research paper I gave at an ICICTE conference in Rhodes 9 years ago...not much has changed!