Call of Juarez is like the Catalyst poster-child in this test, and has been for some time now. ATI spent some resources working with the makers of the game to get it to running smoothly, and it shows. This is the first game that worked well with CrossFireX, and it probably shows the maximum advantage possible to be gained by adding another ATI card to your system.
A second HD 4870 boosted performance by about 50% -- you will likely not see better scaling in any other game currently out.
Watching the Call of Juarez run at maximum quality at 1600x1200 on our HD 4870 (*2) system was very impressive. A year ago, a $200 card might be able to get about 15 FPS where here, the HD 4870 (*2) scored 47.3.

