Just tried the Sleeping Dogs PC Demo. Those 2 missions they have you take on - awesome. I love the combat. It just looks awesome - it looks like an awesome Hong-Kong style martial arts movie. The combat itself feels similar to Batman: Arkham Asylum and Arkham City's combat - so, it's awesome. Throw in environmental kills - too sweet. Nothing like finishing a combat sequence w/ an enemy, grapping them and then slamming a guy's head into a fan or sticking someone's head into a burning furnace. The controls are perfect for melee combat w/ the 360 controller.
One thing sucked - I couldn't move my movement controls from WSAD over to Cursors keys, since I'm left-handed and would prefer to use the cursors. So much for that. So, I stuck w/ the controller - even for shooting. While I'd rather use KB/mouse for shooting, the 360 controller is fine and adequate enough for shooting.
BTW - the game on my PC looks very nice w/ most stuff pumped-way up. Had to turn down one of the in-game graphics features of High-Quality AA to Normal, but everything else was maxed-out and running around 35-40 frames consistently.
I'm gonna have to keep my eye on this one, when it goes on sale...