...and it's good enough that GTA V does not automatically guarantee that Rockstar will reclaim the crown. There are still some things GTA does better, but Sleeping Dogs is more refined overall.
If you haven't seen the game before, check that out.
In short - the game has you in the setting of Hong Kong. The action is brutal and the torture you will witness is intense. Voice acting is superb and has some name Hollywood people such as Lucy Liu, Emma Stone, Kelly Hu and couple others I am forgetting. Combat is refined to be just a couple of buttons, similar to how Batman: Arkham Asylum was, and doesn't feel nearly as clunky as GTA has been since GTA III like 10 years ago on the PS2.
The story is solid, and that's all I should say for those who may not want any spoilers. There are side missions, opportunities to partake in outside the main storyline activities like Karaoke at bars, jack cars, steal safes, etc. One element GTA has that is lacking here, is that they hired actual comedians to do some stand up in the clubs, and it was good material.
The major difference between the two games is plot vs characters. Rockstar games has really memorable characters. GTA IV was top notch (I can still remember almost every major player) and Red Dead also also stellar. Sleeping Dogs characters I do not believe (I can't say for sure) I will remember s well years from now, but that could be a cultural detatch as well, with harder to remember names possibly. The plot, however, seems more adult and plausible than GTA IV and previous versions was. So there is a tradeoff here one for one.
As much as I liked GTA IV and their superb cast, the one gripe I had with the game was the controls were still
a bit stiff, and Niko felt extremely stiff while fighting people. That is not the case in this game, which features more hand to hand so far than gun combat. That and some missions were bullshit hard, sometimes due to bullshit mechanics rather than challenge. That to this point, is not an issue with Sleeping Dogs. My one issue, is some wonk camera action at times while driving around. Wtf is that?
If you really liked GTA series, you have no reason to pick this up. It is certainly more GTA than Saints Row if that was a concern for anyone.