I've been a long-time Champions player; I started playing way back in 1985 or 1986 in the original Champions, Champions II, Champions III era. I've seen the ruleset explode from a simple pamphlet of 60 or so pages to the multivolume rules compendium that it is today with 6th edition. So, I've been around a while.
Dark Champions sets itself to be the "gritty, realistic" genre of play, allowing players to take their brand of justice to the streets with guns a-blazin'. In it, players will stand in the grimy streets, facing down pimps and drug dealers, corrupt politicos and on-the-take cops, and all manner of "street level" of crime. The characters may dress in fancy uniforms, but everything is tinged with grey, black, and red. The inspiration for this is declared to be characters like Marvel's Punisher and Elektra, DC's Batman: the Dark Knight Returns and Watchmen, and (in my opinion) a heavy dose of Frank Miller's seminal "Sin City". It also draws heavily from cinematic thrillers from the 'eighties, 'nineties, and new milennium: Die Hard, Lethal Weapon, Heat, Cobra, and so on...
The introduction runs a little long at the start. From page 9 to page 24 we receive lots of information about "What is Dark Champions?" including genres, subgenres, themes, elements, and so on. This seems to be geared towards the newer player, especially in its recommendations as to how to mix certain genres together. And the Dark Champions elements chapter reads like a Hollywood Blockbuster do-it-yourself kit when we find that Dark Chapions is about: Amazing Escapes, Car Chases, Car Go Boom, Contacts, Crisis Management, Dead Relatives, Guns, etc... (these are the actual section headings). Not what I personally needed, but probably good information for someone who is breaking into a different game system.
For the Crunchier chapters (rules and recommendations), I couldn't decide whether this was a background sourcebook with some rules in it or whether it was a rulebook with heavy sections of background information. I really liked the sections on Forensics and Combat and Adventuring. Sections on Firearms and equipment seemed long and not very enlightening (since the Hero system pretty much allows you to tailor your Ranged Killing Attacks however you want the several pages of add-ons and equipment for guns seemed a little excessive and really not all that useful, except to create verisimilitude in that a .22 doesn't do as much damage as a .45). We receive several pages worth of information about guns; so much so that it began to feel more like an arms and equipment guide with some background thrown in for balance.
Background chapters were generally informative at a basic level. I liked the sections on terrorism and adversary types (stereotypical bad guys like Mafia, yakuza, and triads as well as Robbery Crews and government agencies). This had more of a genre feel than the equipment sections. The section on LIBRA mentions the Harbinger, but no stats are provided (which to an old hand like me makes sense, but may be confusing to a newer player). The five villians provided are solid, but perhaps to be expected all center on their equipment and not very much about their personality or history.
The writing was fairly solid throughout and the artwork ranged from decent to good. My recommendation is that if you are looking for a good source for equipment in a hurry, this is a solid work. As a piece of genre-development, I'm not convinced this is a complete "how-to" to produce any particular genre other than "shoot-em-up" John-Woo style.