Playing with my brother and internet randoms we had a boss round in Horde against a Lambent Zerker on Check Out.
We were doing damage, but only very slowly it seemed. Eventually we were all running out of ammo, even after picking up the dropped weapons, and I ended up spectating the fight of 3 players verses the beast, which went on for a long time before the defeat of our team. We lost twice and everybody else gave up.
Clearly the basic idea is to shoot the boss in the glowing weak spot when it is exposed, so we've got that covered. We beat the Lambent Zerker in campaign (not a spoiler, it was in the E3 reel), but even that fight took a very long time.
I think the map was really working against us, the lack of long sightlines really caused some problems with counter-shooting the charges and dodging w/o getting humped up on map objects.
Do you have any recommendations on how to put her down faster - either the fight is badly paced, or we were missing some key element.