I have something to add to the realism debate. I think when the word "gritty" is used, it is not referring to a dark, cynical point of view. Rather, it is referring to a sense of realism, the feeling that you're actually there in the story. "Gritty" stories are the ones where you're told all about how the hero's feet are sore, intimate areas are chafing, he's dirty and sweaty and aching and tired. In other words, stories where the character has the same problems you would if you stood in a rainy alley for six hours on a stakeout. Stories that aren't gritty would be ones like many of the Silver Age DC comic books, where the dirty details are glossed over in the name of a care-free, fun, purely escapist environment.
But, realizing what people are trying to say when they say gritty, I think we can begin to understand the argument being made here. We are regaled over and over again with how Harry has the some problems as the rest of us. He's often broke. He has trouble managing his schedule. His car never works right, he always has plumbing problems, and he never seems to have enough money or time to fix these issues. In that sense, the series is extremely gritty, and I believe that Butcher applies it to combat rules as well.
Now, understand me here. I'm not saying that my arguments are "Word of Jim." I'm simply sharing the conclusions that I as one individual reader of the Dresden Files series came to, and yours might be different. But as I read the books, I sense that Butcher is very big on following the rules. Rules of physics, rules of how guns work, rules of how cars move and what damage the body REALLY takes when somebody punches you in the head. Murphy is still bound by the real-world consequences of a no-call, no-show at work when she helps Harry out. He also, if you read closely, establishes very firm rules for the wild supernatural stuff. Magic follows strict rules. Supernatural creatures all have things that they can and cannot do. No fae can touch iron, for example, not even the Mothers themselves.
Butcher applies that to guns as well. Harry has never fired more than six shots in a row from his .44 without reloading. Many times throughout the books there are specific mention of how a gun actually works versus how Hollywood and popular culture THINK it works. See the description of how sawed-off shotguns work in . . . White Knight, I believe, or the description of how silenced gunshots are still pretty damn loud in (this one I'm absolutely positive of) Death Masks. Furthermore, we never see, for example, Hendricks using the minigun from Gard's chopper as a man-portable weapon, because it's totally impossible for a creature of human mass to do something like that, regardless of how strong. Butcher has added new rules to his world, because that world contains things that do not exist in ours. But he never flagrantly breaks the already established rules of our world, and he keeps the new rules of his world consistent to each other.
To sum up, the Dresden Files is a very realistic series. Everything in it that is NOT supernatural strictly adheres to real-world limits, and therefore a GM would be very justified in stopping his Pure Mortal player from dual-wielding Desert Eagles.
