Glad you like your new card MikeC.
The ATI AA definitely seems to win in the comparison pictures you posted even comparing ATI's 6X against NV's 8X.
I have had a 9700 Pro for about 8 months and I am still impressed with it. The AA & AF quality just blows me away. I swear it also makes old games look almost new. I just started to replay Vampire Redemption The Masquerade . It runs smooth as a babies bottom at 1600X1200 4X AA -16X AF and looks much better then when I first played it 3 years ago. Grabbed a screen, link below- 144K not 56k friendly