I opened 12 Hirogen lock boxes yesterday, to get a feel for how they might be different from other races lock boxes. I opened 4 each with my Fed, KDF and Romulan char's, with the following results:
FED: Destabilized Tetryon weapon pack (Mk XII round weapon); Gamma Quadrant DOff cadre (7 DOff's); Gamma Quadrant DOff mini-pack (4DOff's); Preferred Rich Dilithium mining claims (6-pack); 33 Lobi total.
KDF: (2x) Gamma Quadrant DOff mini-pack (4DOff's); Destabilized Tetryon weapon pack (Mk XII round weapon); Alpha Deception Field Console; 17 Lobi total.
Romulan: Gamma Quadrant DOff mini-pack (4DOff's); Hirogen Predator DOff (purple); Destabilized Tetryon weapon pack (Mk XII round weapon); Genetic Resequencer extra Hunter Trait & trait respec; 17 Lobi total.
So it sems Hirogen boxes yield Gamma Quadrant DOff's 50% of the time, with Destabilized Tetryon weapon pack (Mk XII round weapon) 25% of the time, and other special items the other 25%. These probabilities are different than those given by a larger test (60 boxes) on the STO forums, but this should give everyone some idea of what to expect.
If anyone has some quantitative data on other race-specific boxes, please post it below!