As I said in my interview with Gavin Hood, I am not a man with military experience. My father-in-law, however, is, and I brought him to the screening. Here are the key points he brought up:
-The placing of orders-questioning Ender and other misfits into their own unique unit where they can think outside the box is an accurate allegory for special forces training as he experienced it, save one detail - nobody on such a team would ever be promoted to commander.
-Said training would also take place over several years. The movie clearly protracts the timeline so as not to have to recast actors as they grow up, but perhaps they should have added some sort of technobabble explanation about how these kids learn three times as quickly or something.
He also found the plot and the movie's message predictable, which I think is fair - director Hood's opinion of what's being shown is always made clear, via directorial emphasis and mood music, while Card's prose let you be more of the judge (again, let us note how strangely selective he is with that philosophy). That it's less didactic than Hood's Tsotsi is a bit like saying it's better than his Wolverine movie - both are faint praise, yet Ender's Game is significantly better on both counts. While my father-in-law felt Ford's Col. Graff was one-dimensional, I think it's the best use of the actor in a long time - the inherent sympathy we bring to that familiar face is a nicely deliberate bit of misdirection.
As a fan of the book, I don't think this is the perfect adaptation, nor could it have been. But it's about as good as we could have expected - the final-final ending still packs an emotional punch - and that's no small thing.