Yeah the AA's algorithm is more accurate and DoF resolution has been increased; meaning the coverage uses smaller pixels so blur won't smear or bloom out beyond the objects it's blurring *much. You will still see shimmering with the AA because it's a post processing solution and they tend to not cover sub-pixel aliasing but it is more stable so you won't get the nervous jumping, flickering pixels around aliasing. Shadows are cleaner as well and tend to be higher in resolution in the distance or won't flicker with huge low res pixels.
It's not that it's better; it's more accurate/stable with a lot less artifacts/noise.