The only reason I didn't get Kane and Lynch was because I also wanted a lot of other games from Square and I'm going to just get the Square pack at Christmas. I saw the reviews too and I kind of thought maybe they got downrated a full point or so over violent content rather than quality.
There wasn't anything notably violent or gorey about Kane & Lynch 2 (except for one particular chapter which I won't spoil). Actually, I'd say the biggest problem with the game is just it's length. I finished it in 4 hours. As fun as it was, I wouldn't have payed more than $15 or $20 for it. For five bucks though I'm very satisfied.
One of the best things about the game is just it's presentation. Most people would get motion-sickness from the shaky camera, but since games never make me physically ill I actually thought it was really neat (the colors, strobes of light, and buffering artifacts really complete the effect). The whole game plays out like an amateur snuff film, as if someone is running behind you with a shitty MiniDV camcorder. The protagonist is a hard-ass overweight bald guy, along with his partner, and it's entertaining to hear their random bantering and conversations with each other through the game. The way they yell and react as all kinds of crazy situations play out in front of them is really quite amusing.
The game has awesome sound design too. It doesn't have any real music to speak of, but rather, a series of soundscapes and ambient noises, which echo through the apartments and streets of a filthy downtown Shanghai. Bits and pieces of music and other interesting noises are played... I don't know how else to describe it.
The cover system is fluid, the set pieces are awesome, and the auditory/visual effects are like nothing I've ever experienced in any other game. (At one point, you're barreling through a series of Chinese sweatshops, which was crazy). It's some pretty brilliant shit.