Question RenderTexture, Anti Aliasing and Graphics Settings

So I've been wondering if it's worth it to have the Anti Aliasing set on the Render Texture directly instead of the camera rendering to that particular texture. I hear it's pretty damn expensive, and I have like 2 of them on at all times. Because honestly, no matter if I choose to turn it on the camera or the texture itself, I see very little difference in the overall image.

Also, how do you guys deal with graphic settings in regards to RenderTextures? Just list all the ones you use in a "Settings Manager" script and change the features depending on the level of quality the user chooses?