Originally by: OFFICERoftheLawL
Is there a significant increase in isk/hour ratio when comparing a "normal" highsec lvl 4 mission with one given by the pirate faction?
Yes, but that comes from the fact that rewards (both ISK and LP) are affected by system security status (IIRC, it's truesec, not listed sec, truesec goes into the negatives, down to -1.00).
Also, LP for pirate factions tend to be more valuable than LPs for empire factions.
Those two factors combined actually mean that in some cases, blitzing L3s for pirate factions can be more lucrative than regular empire L4 mission-running.