You are 20 (or more) level when you take this perk, enough of your suffering, you should now regenerate ALL the AP after killing someone in V.A.T.S.!
And Action boy should have more AP not just 16! Better 25 like fallout 3! Afterall the V.A.T.S. is a game feuture and should be used more, thus producing more fun!
Nope. Hated Grim Reaper's Sprint in FO3 for reasons already articulated. Broken from a balance standpoint. You became too much of a god, so Beth had to create Overlords and Albino Radscorpions and Ghoul Reavers, which overwhelmed every other npc and travelling merchant in the game. (The brotherhood of steel are supposed to be a match for the supermutants, but a solitary overlord with a trilaser could reliably overwhelm every guard outside the citadel. I'd bet 2 overlords or 4 reavers could clear the entire interior) That still wasn't enough, overlords and hillbillies had to get massive bonuses for trilasers and lever action rifles. The whole game spun out of control, because the Lone wanderer's combat prowess was plain silly.
As said already, VATS was an "I win" button. Broken Steel/PL enemies aside, you didn't have to think or plan through your battles much. No use of cover, no real need for stealth or tactics. Get a decent gun, hit VATS, chain attacks till everyone was dead while taking squat for damage. <_<