Zipper Interactive's community manager, Jeremy Dunham, has announced over on the US PS Blog that MAG has entered its fourth Beta phase.
He also announced that over 6000 changes have been made since the previous Beta.
One change involves Shadow War Bonuses, which according to Dunham: "Depending on which Private Military Contractors (PMC's) are leading in the number of contracts owned, the entire PMC team will earn different bonuses based on gametype. Leading in Sabotage adds experience points, leading in Acquisition increases leadership aura distance, and leading in Domination decreases tactical strike cooldown time."
The devs also improved the ranking system, character hit detection, leadership abilities, and experience points.
Loads more about this can be read through the link, there.
Game's out January 26.