Yep. 280x is basically equivalent (clock speed wise, not over clocking wise) as the Asus Matrix Platinum 7970. Ironically I bet you could juice the Asus 7970 up past the 280x.
I only follow this amd/Nvidia stuff once every couple years so I don't know what has happened over the past 2. That being said, I'm getting sick of this. Give us a date and then release your product. I know that aMD is struggling- especially when you consider that the 290x will be the best card for all of 1-2 months before Nvidia comes out with the Titan ultra or something. I'm trying to stay product loyal here but I can't see why I should.
To add insult to injury, the 290x beats the Titan WHEN using mantle per AMD rep. Kind of a big caveat since 1 game supports mantle and it cost and $8 mil in bribes to snag it.
Consoles will not use mantle therefore ports will not use mantle. Maybe a few games here and there but I doubt a manufacturer is going to choose sides in the amd/Nvidia fight (if they did, they'd choose Nvidia who has larger market share). Mantle will either fail or be shared with Nvidia in the near future.