I know not many people put much faith in Eurogamer but here's their extremely positive review for Gears 2.

Closing thoughts:

Like the original, on one level, Gears 2 is a brilliant advertisement for Unreal Engine 3, glorying in soft-body physics, glinting textures, and massive explosions. Even after a year of non-stop eye candy, Epic's series provides some of the most fiercely pretty visuals you'll get the chance to look at, even if its world is so charmingly ugly. Yet on another level, the game's a calling card from a developer that continues to mature in design as well as technology. The first game slowed down the crazy pace of Unreal Tournament - forcing you into using the environment every bit as much as the weapon-set - and the sequel continues to build on that with ease, but alongside the bare mechanics, Gears of War 2 shows a new interest in stories and varying the action. Best of all, it has the native intelligence to bring both aspects together.