Hmmmm HD 5870 is OverHyped, OverPriced and Underperforming, YES !
In some games (HAWX) this cards is 13 % faster than hd 4890, it has DOUBLE count of 4890 SP and is more than twice more expensive.
Resident evil 5 - 19% faster than 4890
Crysis - 34 % faster
Left 4 dead - 43 % faster
FarCry2 - 54 % faster - Remeber it has 2x shader of a 4890 for 50 % boost, given the price a big let down from ATI

.
Stalker CS - 53 % - same story.
On average 37 % boost compared to a hd 4890, should be 80 %, i dont dream about 100% boost, gpu efficency, game optimisation etc makes fps loss.
anyway they ask you to pay TWICE the price of hd 4890 and you get 37-40 % increase.
The only positive points are : good performer at 25x16
Low watt useage
I'm not a ati either NV fanboy, i buy best power for my $, not brand. I'm not here to kill ATI, just saying we customers should stay reasonable and not get scammed.
My advice : WAIT, price drop + new drivers, Ati made big improvement on that side. Besides wait for NV response for price war domino.