The only difference between Assimilate rank 4 and 5 is that "On a headshot kill, instantly restore ... 30% of your current (not maximum) ability energy.". Often after surviving a standoff my entire overshield is drained during the firefight, but as I'm running a fully upgraded Adrenaline shield, I'm left with 44% shield. The question I have is whether or not the 30% "extra" on a headshot would be based on this 44%, giving about 58% shield remaining on HS kills? Or is it calculated from the shield you had right before the kill. I'm wondering because in the second case I might save my ISO4 for other implants.
Assimilate 5 has been bugged since release, and not sure if it ever got fixed. Unless someone who already owns Assimilate 5 confirms it actually works, I'd save ISO-4 for now.
