The last benchmarks that I saw where when the 780 came out and there were mix opinions as some reviewers showed the 780 as a slightly stronger card compared to the 290x and others the opposite. Have not seen any new benchmarks.
The 780 was never a real match for the 290x, the 780ti was the top card for a long time. AMD have updated drivers that have been increasing their cards perfomance quite well. That's why many of the new charts have them 290/290x beating out their counterparts in many games.
Price/Performance its hard to beat an R9 290 at the moment.
