Observation

[Blackstone]

For what it's worth I've noticed that briefcases open with documents at a higher rate if the cases were acquired via PVE. Most PVP cases seem to give valor or units. I'm currently at 7 with 5 days to go.

[Angirl]

I have opened 10 now, I have 7 docs, 2 loot items and 60000 cash. Not noticed which gives better odds as I have had docs from PvP, PvE and missions.

[ObamaSux]

I can't find briefcases and the ones I do get raided as soon as I get them. A Dozen cases, opened 2 docs, 250K so far.