i have the 6800gt as well. the color reproduction to me is fine and according to the article linked by ribspreader tey are exceptional. i can only tell you what i see and that is that farcry, rome, sims2, ut4 look tremendous. i still have yet to watch a dvd but i will tonite.
the "hardest" part is the initial setup, mostly because the controls suck. i think i have it at the factory defauly now anyway and control it thru the 6800. i might try to change it on the monitor but i am waiting on word from hyundai about drivers. the disc that came with mine was unusable/couldn't open the file.
edit=BTW, now that i think of it more, there was a thread here a few weeks back in which one poster had emailed hyundai regarding the bits. i'll look for it in search when i get a chance, but it was like 4 pages deep in a dscussion IIRC.