I wanted to know if my Imp loses some dps uptime when chasing Direhorn Spirit and switching back to Horridon so I ran some simulations and compared results to my logs. The logged fight in question lasted 720 secs so I simulated a similar fight.
SimulationCraft (530-2) shows Imp should cast 241 Firebolts during 720 seconds Patchwerk-fight (2.99 sec interval). But my logs show Imp casted 272 Firebolts (averaging 2.65 sec interval). 272 Firebolts is 12,9% more Firebolts than simulated. Imp's Firebolt should do 11,6% of my total damage, so 12,9% more Firebolts should mean 1,5% higher total damage (in 720 sec simulation). That would put Fel Imp ahead Observer by 0,47% (unless Observer results are off as well).
So is there something they changed in 5.3 and Imp is generating energy faster or is there just a bug in SimulationCraft?