I've complained about TF stories about military personnel who don't seem to have the competence of a rent-a-cop, much less some sort of spec ops specialized operators.

Today I found a certain fic series I had seen before, and the military content is exhaustively researched, but it has absolutely no significant characterization whatsoever. Even the porny bits are generic. And even then, people still act like idiots when the plot calls for it, and the writing style feels like he's trying to imitate about six writers at once.

So, let's review; research is nice, but you only need enough to make it feel real, and try not to have your heroes be idiots.