Alex,
You're being a bit picky, IMHO.
For one, the AI in Gears is pretty darned good overall (yeah there are a few bugs with the Bugs). The Locusts don't to the typical no-brainer rush the enemy but take cover and snipe. And their aim are pretty good, especially at the later hardcore and the insane levels. You HAVE to take cover in those levels.
The interesting twist the game has on reloads and the timing of hitting the sweet spot for the best reload time is pretty cool. And some of the weapons are great. Sure a chainsaw has no real place in combat, but there is something extremely satisfying in ripping into one of the Bugs. And the Hammer of Dawn....SWEET!
And we both agree it's one of the best looking games out there right now. I especially love the little jumpy camera effect it has when you crouch-run.
I am a bit biased in that shooters are my favorite game genres. I've played a lot of them and Gears is pretty high on my fun list. A nice way to unwind after a day at the office.