Well, I got my curb stomp achievement a few days ago. I am now working on getting a few other online achievements.

My closest is executions I am a little over 80. I should hopefully get that this weekend.  As for the others I am at about 50 something headshots, 60 something revives. Only about 40 something chainsaw kills.  I am not playing in a manner to simply achieve these goals though. I just play normally and if I get a headshot or something then it's a bonus :)