Since almost all sites tested 290X in quiet mode, but most people buying 290X either water cooled them or bought after-market versions that solved temperature and noise levels, the reasonable non-biased comparison on an enthusiast forum that can be made is 290X max power tune vs. 980 max power tune if we are talking stock performance.
Computerbase is about the
only site that actually did this.
980 max vs. 290X max
1920x1080 =
+21%
2560x1600 =
+12%
4K =
+8%
Average: 13.7% or ~ 14%
14% with 100W less power draw is comfortably ahead but the 980 is 1 year newer. The same people in that Motley fool article never provided the same accolades when $399 R9 290 forced a $650 780 to drop to $499 and 290s destroyed a 780Ti for $100 more. It's these double standards that are the most frustrating. 970 is slightly faster than a 1 year old 290 but it's only $70 less. That's good, but not a revolutionary performance/$ leap in 12 months. It's only amazing in light of NV's laughable $699 780Ti price and if you only buy NV cards.
The impressive thing about the gtx 980 as a whole is it outperforms 290x by that 14 percent while consuming 100w less power on the same maufacturing node. It beats the 290x on all levels, while a gtx 970 matches it for performance for far less power. You try to downplay the new cards from Nvidia because they are one year newer than Hawaii, but being one year newer doesn't meant they are guaranteed improvements like you see with the gtx 980.
Case in point, look at the r9 285. Note they have the same power consumption or around the same ballpark of the new gtx 980. They were also both released in September. But the gtx 980 has 75% higher performance. That is massive.
What this means is right now, Nvidia has an overwhelming architectural advantage. Considering there wasn't much of an improvement between Tonga and hawaii performance per watt wise, a big version of the r9 285 could very well perform the same as hawaii before it hits the power wall the 290x hits.
On the other hand with the gtx 980, if Nvidia made a big titan version of it, you still have 100watts to go, which means you could eek out another 50 percent more performance. This could translate into a card that is 60% faster than a r9 290x. And this is with the card being held back by being manufactured a 28nm. If Nvidia got a die shrink(double transistors) + maxwell, you could be looking at the single biggest increase of a newest generation of cards ever. Bigger than the gtx 8800, bigger than the 9700 pro.
Pricing is the only thing that hurts the review of the gtx 980(this flaw isn't present on the gtx 970), but from a technological perspective, they are worthy of the praise they get. And the generally balanced nature of these new cards are what is causing the reviewers to go wild and people to worry about AMD longterm ability to compete.
R9 285 and the gtx 980/970 platform are really a preview of what is expected from both companies in the next year or so. The problem is the gtx 980 is good and the pricing reflects that, and the r9 285 generally sucks in comparison and its pricing reflects that.
But considering you think the 290s destroyed the gtx 780 ti's, I am not sure if you can appreciate the new maxwell cards anyways.