Micro, Para .45, and the Enforcer are the best.
Seeing some of the areas of LL makes me really sad we didn't get any new maps...
I loved the MP for a long while after it came out and I played for a bit yesterday but I just can't get back into the game without any new maps or game modes. I always do incredibly well and carry the absolute fuck out of my teams, but the game just feels so easy since 95% of players are so horrible at the game that I don't even have to try.
Arena was okayish but felt very similar to Survival. My big gripe with it was some of the absolutely unfun modifiers they have like headshot/melee only which wouldn't be so bad if the modifier was always like x3 damage for headshots. I played some Crushing and got that and it felt basically impossible because of constant shotgun enemies that never have to reload with armor and helmets.
Of course it is doable, but that isn't the point, it just wasn't fun going through that.
Modifiers when done right are fine, like mirror world and such.
Melee and headshots only though, completely unfun.