Is Shotgun Surgeon worth taking on a VATS-using Guns character, or am I better off just keeping a lot of AP ammo on hand for other guns that have lower AP costs?

Some background if you're interested: I'm getting close to the level cap. I've already picked most of the Perks that seemed must-haves for my play style by now, but I'm trying to figure out what to do for the last one. I do a lot of close-quarters fighting because my Fast Shot trait means long-range fighting is less of an option. Typically I'm using 10mm Pistol, That Gun (with AP ammo), or an SMG because shotguns take so many Action Points. If I don't take Shotgun Surgeon, I'll probably just take a second rank of Action Boy instead, but I wanted to know whether it's an uberperk I simply should not pass on...

It depends if you like using a Shotgun a lot. It lowers DT of an enemy by 10 when using shotguns. I was thinking about this too but probably wouldn't pick this up til later in game when I find a decent shotgun. It really depends on what the DT of most enemies that you come up against will have. Does 10 DT sound like a lot to you? It does sound like quite a bit but I don't know if I'd be using shotguns enough to get the benefit.

The same goes for the Cowboy perk. I was thinking about this as it gives lots of extra damage for several different weapons but depends on what kind of weapon you are going to be leaning towards. If it's Energy Weapons, it won't help you out a bit, but if you go classic guns, it will be very beneficial.