What's the appeal of this movie?

I know. I know. Why come to this forum to bash a film. I guess it's that I did like the storyline. The drawback for me isn't that it fell flat otherwise. That would be a compliment for this movie. Instead any thing technical–music, visual symbolism, sounds–were so conspicuous that they drew me away from the movie. One moment, for example, two flip phones are whisked shut, this sound is dubbed with the sound of knives swiping against each other. It was not just irritating but funny. I think the best example of how badly the artistry of this movie is was when Corrigan is chasing down Sullivan–this scene at night felt very Gotham City, early Batman movies. There was the smoke puffing out of the streets and the bizarre "funhouse" moment with the mirrored glass windchime, and you get a swath of eyes.

I also could absolutely not believe this film was released in 2006. It felt very early-'90s, the latest. It was cheesy in so many ways, and I rarely think things are cheesy (I am probably missing out on at least some good things, and I mean that earnestly). The ending was very contrived and convenient, and maybe I am just saying that because I didn't get the happy ending I wanted (Sullivan revealed; Corrigan free). Was it intentionally so heavyhanded?

I said I enjoyed parts of the storyline. However, the linchpin of the movie was another obvious symbol; two informants coming up against each other, somehow mirroring each othe. I really wanted to heat more of Sullivan's story. He seemed sensitive and intelligent; I think that could have been capitalized on better than just making him this loyal "kid."

Extra thought: I really liked that Hawthorne quote and although the Flogging Molly-esque song was another jarring moment, (especially how it stopped for a few seconds and then came back; okay, Scorcese, you have sufficiently tortured us in this movie if that's what you were going for) it seemed like a song I might like.

So yeah, what's the appeal?