Maybe you're a cop or security guard, maybe you're a guy who lives in a place where you can't carry a firearm, maybe you're just someone looking to fill the 'use of force' void that exists between shooting someone the bird and shooting them between the eyes. Any way you look at it, lets not beat around the bush here... Anyone buying this light is doing so for one reason only, the 'light' aspect being totally secondary to that one reason. It's a club that doubles as a flashlight.
So, how do we judge it on the objective criteria?
As a whuppin' stick, it definitely works- so well that some 'kinder, gentler' Police Departments don't even allow it anymore. Kind of a bummer that they discontinued the thinner 6C; barring finding one second hand and paying a real scalpers price for it, the 5D/6D is the pretty much the only 'in production' option in the Mag line for a "big defensive flashlight" but that's OK. Unless you have very small hands, the 6D is perfectly controllable.
It's big. Really, really big. The light itself is about 19.5" long- a foot and a half- in total. When weighted down with cels, it's heavy, too.
You will want to tread lightly with this, as it definitely would generate enough striking force to fracture a skull, break bones. Be damn sure you're legally justified to use it, if you ever do use it. You can hurt someone with it. It's does cut a pretty intimidating profile. Walking around with one, it's almost as if you're carrying a bat. In some situations, this is OK. In other situations, where drawing attention to yourself isn't the desired outcome, you'd definitely want to leave this one home (in this regard, probably worth noting that given its weight, this is essentially a two handed club. I'm a large guy who has decent enough working strength- swinging a six D-cel flashlight with one hand is pretty slow going. Slow enough that you might risk your adversary grabbing on to it)
As far as brightness, it's bright by 'bright enough' standards. Not bright enough to impress flashlight geeks who obsess over marginally relevant technical details on internet forums, plenty bright for Average Joe to use for real world stuff. Unless something has changed, these are still shipping with incandescent bulbs, which aren't anywhere near as bright as a good LED (for example, the Maglite 3d LED torch is significantly brighter)... of course, let us not forget the reason we bought this in the first place. The 'flashlight' part is a secondary consideration, or, a primary consideration inasmuch as it allows us to carry it around in places where the same thing absent the flashlight function would be considered an unlawful bludgeon or club.
If you want to juice the light aspect up to balls-out bright, terralux makes an upgrade that turns the thing into a portable sun... It's pricey- three times the cost of the light itself- but it does add a monumental upgrade in brightness (700 lumens), which can be quite practical. If you shine that into someones face, they're either turning away, or, if they're really determined to keep advancing, they'll be doing so blinded and/or with their eyes closed, at which point we option the 'club' functionality.
I don't throw around the five star rating too often, but this is a five star piece. Right now, as of October 2010, with Amazon free shipping on purchases over 25, you can get one shipped to your door for right at 25 bucks. Is this worth 25 bucks? Hell yeah.