We have been getting 2 keys max. Most of the time my partner doesn't get a key or only gets one. I get 2 every time. It seems to be damage based, but we're not sure. Sometimes he kills way more than me, but I'll still get 2 and he gets 0. If you only do the objectives you will get 0 keys. We haven't been able to figure out what determines how many keys you get.
Theirs another mission, in the Madera Area, with a similar goal, or it might be norther Marin, by the Madera border. Essentially go in, activate 2 things, and done. usually awards me 5 Keycodes, now according to the patch, only emergency's are removing keycodes, so my guess is people will go to speed running The Motherlode, and 101 Explosions, I can consistently do both in 7 minuets with my clan-mates now.
that's 5 keys, good money, and if I run with my Officers, at times we have loot for clan, and group((each member)), and once I had self going as well. and Co-Op instances have higher drop rates, now add gun drop rates being increased post patch, my guess is a co-op instance can earn 5 keycodes, and nearly 200k in resources per run. Now, you can consistently go threw in under 7 minuets... well that's a lot of Keycodes in a short period.
"Impossible is not a thing, nor is it an action, it is simply a state of mind, for once sailing to America, was deemed Impossible" - EmoPyroNecrosis, yeah I said it... so :P
Founder if the National Arkhunting Association guild
Creator of the exploding watermelon,
Maker of the invincible chicken,
Farmer of the Doesy Does,
That guy who effed your mom last night,
EmoPyroNecrosis... Did I mention I also love Pi?