Yeah, I fire off short burst and they work most of the time. Just not in that desert map (which I understand because of the "realism," but then enemies are killing me across the map with their rifles...?)
And I know I can filter, I just haven't been because I want to check out all the maps. And from what I've played so far they're really good; just not that desert map.
Did you play as Helghast or ISA? They really need to tone down the lights of both sides, but the red helghast lanterns can be spotted anywhere.
As much as I didn't like Halo 3, playing it on Legendary was amazing. The things the AI would do would always impress me. Throwing down a shield grenade to advance to a new cover point, flushing me out with a grenade only to flank me on the other side. It was always a challenge.
The AI here is better than COD4 which is a monster closet, but much much worse than Halo 3s.
I don't know about Legendary, but I'm playing through Halo 3 on Heroic right now and the brute A.I. doesn't strike me as doing anything particularly interesting. Specifically, the brutes seem to be downright distinguished mentally-challenged and almost completely unresponsive to my medium-long range attacks, which is made all the more obvious by the sheer size of these barely moving targets. Yeah, they throw down bubble shields, but then they also stand right in the middle of the shield until it expires, so all I have to do is wait for it to deactivate before picking off the target. The spice of almost all encounters comes courtesy of the combination of jackals and grunts, which is fun but a bit weird. Maybe my memory of Halo A.I. is a bit rosy, but I really miss fighting elites.
As for KZ2, there was one scene where I managed to really exploit a scripted entry, and that cheapened the experience a lot. Felt a bit like Rainbow Six Vegas at its worst, and I wasn't really expecting that. Of course, right after that I was successfully flanked, so hey.
On another Halo note, I think one thing that really separates Halo from KZ2 (and most other shooters) is the grunt variety. They don't seem to be very popular, but I always felt that the grunts added a lot to Halo. Personality, I guess, and while they're never difficult to kill, they are always fun to hunt.