Okay, let's get this long review started, some good parts, some bad parts and whatever else. The short of it all, though, is that this is pretty much just an action movie franchise in manga format with some small additional parts. It doesn't truly have any real main character, at least not like in many other stuff where you have "THE" main character, rock is too irrelevant and shows up too little for that. Some light comedy along with some super censored "gore"... Well, that's about what you'd get here, it's good enough to read without getting bored. Now onto the long one:
Something I always found annoying is characters that live within an inch of death but has no motivation whatsoever to get stronger. It's good that the main character actually develops his personality and gets affected by his environment, slowly turning into someone more used to the lawlessness and deaths along with becoming more and more insane until he pretty much becomes like everyone else, but I am absolutely f*cking fed up with his idiocy. Guns? Nah, let's not use that when firefights happen every day and I'm on the brink of death 24/7! Martial arts of some kind? Nah, let's go on being a weak salaryman whose only good trait is that he's pretty good at talking(when it's convenient, of course) and has guts along with being relatively good at making up tactics.
I mean, which even remotely sane person would deny himself the use of firearms and combat training when you're close to death every day and would've died hundreds of times already if not for being the mc? It's about as logical as trying to become a professional painter but denying yourself all the tools you need to practice or trying to survive after being stranded in the wilderness but refusing to use makeshift weapons because you don't like having to kill for food or not eating food/resources you can get your hand on simply because you "don't like the taste/look". You'll f*cking eat it and you'll like it, it's as simple as that unless you want to die, but clearly this mc must be suicidal or just retarded in some ways.
I can't say I'm fond of him at all, he's one of the least likable characters in this manga, especially later on when he starts feeling more like a typical low-level villain, the type who'd get killed in a few chapters as he's all full of himself but can't back it up(it all works out because he's the mc though). He becomes the type of character that you not only don't root for, you actually want to punch his face in or kill him altogether. Well, he kinda shifts between that mode and a more likable one, but no matter which, he's never a good character. The author is obviously trying to develop his character and let us see how he changes, but that doesn't change how he's annoying or even obnoxious most of the time, who cares about his changes when you don't even like him in the first place?
By the way, it's actually very similar to an action movie in many ways, wouldn't surprise me if the author got the idea and inspiration from watching action movies. A lot of explosions, guns firing, everyone's packing heavy firepower, somehow no one can hit anyone with bullets no matter how many they fire and it doesn't matter if they're in cover or not, there's a lot of vehicle action where they shoot each other from vehicles and the fighting style is pretty ridiculous and completely unrealistic, like wielding two guns because it's cool(the author even mentions himself that it's extremely impractical and no one would use guns like that in real life), there seems to be endless amounts of bullets, the government forces, police, army and similar stuff is generally utterly worthless and uninvolved with some exceptions, people can do things that is not possible because it looks cool such as biting through a metal blade and crushing it to pieces with your mouth, well, you get the deal, the usual action movie-like stuff, although the biting through blades part is more like other action manga than action movies.
It's pretty interesting to see a manga version of action movies but at the same time, it also means it suffers from many faults that action movies have, such as forcing one to suspend disbelief all the time and being unable to feel that attached to the characters. I also don't really feel that immersed, instead it's just pretty cool and interesting. Honestly, I don't feel like there truly is a main character in this story because the main character, rock, plays such a small role overall. He's just kinda there for everything but he doesn't help much, instead serving as someone who causes things to spin out of control and go in kinda unexpected or foolish directions, usually thanks to him still being fairly emotional and caring about others. Unlike in many other stories, this manga just doesn't really revolve around him, he's just part of it, as one of the main characters rather than THE main character, you get what I mean.
Being action-movie like, it also doesn't have any deep story and instead is kind of episodic, we have small arcs with "missions/events" and not much coherence overall. The characters are pretty static and we don't know their motivations for things, they also don't really have any goal. It's easy to see that they're not trying to fulfill any purpose, the characters are just going with the flow and their past and motivations are unimportant or pretty much not even something that exists. It's not as if they're trying to become rich or have any other clear-cut goals, it's more like they're enjoying themselves and waiting to die in a firefight, almost having given up on life, this in turn makes it very hard to feel anything for the characters since they're pretty soulless. In a way, it's actually similar to "hellsing" and "drifters" with less insanity, chaos and useless dialogue(although it becomes increasingly more chatty later on with twisted philosophy that just isn't interesting to read about and only takes up space, being easy to come up with is its only merit, that's when it truly takes a nosedive in enjoyment). Rather than immersive, it's aimed to be entertaining and high-paced while lacking anything that would slow down the action and momentum. It's interesting, but not what I would call top-quality or awesome thanks to the many lacking parts and lack of anything that would truly capture my attention and immerse me into the story(Well, the failure to immerse me also results in it starting to become more of a dull read the longer you go, 80-100 chapters of around 2000 pages is the perfect length as it ends just before you get bored for real).
Well, enough on that. The art is to my liking and I feel like it's pretty good for its age. I have a very hard time liking certain older works because the art looks like scribbles, either chaotic or just out-dated and feeling pretty immature or unfitting of the story. The comedy is there, but I don't feel like it's anything exceptional. Never once did I laugh out loud, but I did manage to smile or chuckle slightly a few times over 100 chapters, although it's not laugh out loud material, it's pretty damn hilarious when nuns and priests of a church are packing serious firepower and is crazy as f*ck after all, especially when the ancient old nun personally comes out wielding a huge handgun, starting to fire crazily while preaching and talking like an old nun would. I mean, that's so damn surreal, I loved parts like that, that church is one of my favorite parts of this manga, hands down.
So, should you read this? Do you like action movies? Do you like people dying but without any true gore(we're talking cut off limbs that just become black spheres, nothing graphic, no innards or anything else, the most disgusting stuff would be a shadowed guy with some needles sticking out of his head that we can't really see or a gunshot wound to the head of a child, truly light stuff)? Do you like light comedy and the "dark side of society"? Do you like it when there's no true main character and it's more about the team as a whole than an individual person(although, honestly, it's mainly about revy, rock and the russian female mafia boss, dutch and the other guy are rarely that involved and keeps to the background)? Well, I guess this is for you. I thought people were exaggerating about it being like an action movie, but it's completely true, this is nothing but an action movie franchise with several sequels in manga format. Sure, there are some other parts as well that you wouldn't find in an action movie, but they're truly so irrelevant or small that it doesn't matter at all. As for me, I can honestly say that while it's readable, I don't really like this author's writing style nor will I care to read anything else written by him. One of these are enough, his style is not good enough to be interesting through more than one manga/story, especially since I don't agree with his views on what is "cool" and "hardcore".