I hated Peggy. I thought she was a misguided byproduct of a highly unethical lifestyle. She was completely unaware of the horrifying consequences of her fiance's method of breadwinning. All her teenpop philosophy made me a bit queasy because it was optimism built on the corpses of Hong Kong's poor.
I am not liking the plot (a bit past 50% story completion now), since the game doesn't convey to us that we're supposed to be getting attached to certain characters. I spent Winston's entire arc wondering when I was going to throw my cards out on the table and turn this guy in. Since everybody around me is committing atrocities, I have difficulty liking any of them. The character I relate to the most is Raymond, simply because he hasn't yet revealed himself to be a sociopath (even if he does force the main character into moral crises).
The only criminal I find likable is Jackie. Everybody else spends a lot of time shooting up businesses filled with innocent bystanders or accusing people of being a cop. Maybe it's the fact that it is explicitly stated early on that the people around me brutally tortured the last undercover officer they found and buried him alive which makes it difficult for me to consider any of them good friends.
I liked the story a bit more before I got my first gun, too. Before then, it was unique in that death seemed to be a big deal. You see a man get shot in front of you and it actually freaks you out a bit. What? The other gang killed _two_ of our boys? I'ma go fuck 'em up! Then we slaughter a dozen guys indiscriminately during the first gunplay mission, and from there it's a lot of blowing up cars with machine guns and mowing down rows of gun-toting thugs. If I was better at my real job (being an undercover cop), I would have left the Sun On Yee to their fate and let the hordes of machine-gun wielding gonzos tear team to pieces (though that may be unfair considering the action movie influences).
There appears to be a cast of extremely minor secondary characters who give you side missions. I recognize one for his notable appearance, but the others I generally can't name. Which made it awkward when you find one of their dead bodies and cry over it a bit.
Now there's all this political stuff going on and I can't really get into it because I'm not familiar with the entirely new cast of characters they've introduced for the second half of the game (nor can I get over the disappearance of the first half of the cast, some of them inexplicably - will we ever seen Emma Stone's character again, or has she left for the rest of her backpacking adventure?). At best, I know I should dislike the guy who keeps trying to murder me and every innocent bystander within 50 feet of me, and that I should have only a tenuous trust with the shrewd woman who opposes him.
That said, it's still an okay game. It keeps me entertained. I like shooting the tires out of enemy cars and beating people up in parking lots. Missions are fun when they don't involve cover-shooting. The promising storyline lost its footing about a quarter of the way through, however, getting lost in somewhat morally ambiguous territory. So it doesn't compel me. GTA IV, despite not being quite as "smart" as this game tries to be, could hold my attention for longer periods because I cared about some of the characters other than the one I was playing as. I'm giving Sleeping Dogs a 7/10.