Insaniac, I think at maxed skill and x4, the chance of fire per shot is so high that there is some redundancy.
Okay, so I figured out AA. Nhancer does it fine after all- you need to manually activate the profile and use the Gamebryo compatibility mode, it's way better than the standard UE3 one for some reason. I can post detailed instructions on how to do this if you guys would like!
I chose an object I noticed was heavily aliased for screenies. Can take shots of whatever you'd like at various settings (or even bullshots with crazy high AA if desired):
No AA:
16x MSAA:
2x2 Supersampling:
Pretty stuff. Even at 16x, you have to get quite close to notice the aliasing at all- about the distance I am from the skull.
In my testing, though, I definitely begin to see why Gbx decided not to include it in the in-game settings.
1. It is a sizable performance hit. I have a monster rig, i7 940, SLI GTX 260; 16x is a pretty much unnoticeable hit in FPS (and what I will be using from now on), but 2x2 super is just a bit too much of a drop. It's what I'd call "playable sub-30," and a far cry from the near-constant 60 of the other settings. I think this is largely because the thick edges of the art-style require a lot more anti-aliasing than your standard borders, putting a greater strain on the GPU.
2. Really, the game at high resolutions is still awesomely beautiful without it due to the art design. I think this combined with #1 made the devs think, 90% of people playing this game won't be able to use it and will be frustrated when they try, so let's forget it for now." I, of course, would have still preferred an in-game option.
3. Dynamic self-shadows used by the engine, like those on iron sheet wall/fence, when moving your character quickly, don't like AA. They freak out a bit. It's easily noticeable but hard to describe. Not enough for me to prefer No AA, but, definitely a compatibility issue that I can see leading to removing the option.
4. I like pie.
Anyway, I'm really loving 16x and I may try to find an even sweeter spot (a Q setting or maybe even CSAA).