get the 7800GTX for sure dude
it has cinefx 4.0
and it has more RAW POWER
when you turn aa on on this card it kicks the 6800ultras ass
plus it has extra pixel and vertex pipes,
and it has a new Antialiasing feature called Transparent antialiasing
have you ever seen the fences in half life 2 when you can see another fence behind it?
well this transparent antialiasing filters the fence behind the fence as standard AA couldn't do this
the 7800GTX also runs ALOT cooler due to its new microprocess (DIE SIZE), it also requires less power overall, and it kicks ass in games
would you like me to pull up Guru3d's review?
temps are between 40-75 (which is very safe on the vid cards of these days)
just make sure you have good airflow throughout your case
heres the review
http://www.guru3d.com/article/Videocards/229/
don't try acessing guru3d's home page, i believe they are having server difficulties right now, so just enjoy the review