Hi there, i am a 7680x1440 user and at the moment i am using a crossfire r9 290x both watercooled.

I am asking myself if upgrading to sli 980HC would be worth it or if i should wait for 980Ti.

AMD works very well at higher resolutions and they gave eyefinity some nice features that Nvidia still misses in Surround, but it's also true that i go for horsepower to push such resolution.

Ocaholic pushed a 980 to a incredible clock, of course it's silicon lottery but what about EVGA? Do they get standard chips or do they get the best?

If you have a pair of water cooled 290x's then no the 980 is not worth "upgrading" to, unless you just want the superior polished feel Nvidia provides along with all of its side features like G sync, PhysX etc etc.......

imo keep the crossfire..

Also, you have to take into account not just the hardware.
And this is just personal experience, and my opinion..
STAY AWAY FROM NVIDIA SURROUND if you already have a good Eyefinity setup working properly.
Nvidia surround needs more work and better support from nvidia.

That mean example EVGA GTX980 Superclocked is stronger than GTX780Ti GHz Edition 1085MHz, Inno3D Herculez 1085MHz and K|NGP|N Edition 1072MHz. Even if my card offer something higher score than GHz and HerculeZ she is stronger only from reference GTX980 and only for little.
Anything faster than pure reference GTX980 is fastest card at the moment. Example GTX980 SC reference cooler.
Because difference between GTX780Ti and fabric overclocked GTX780Ti is biggest I saw ever, more than 2000 points in GPU Firestrike.
Because of that NVIDIA and want to limit us with voltage, example no reference GTX980 faster than my GTX780Ti, and NVIDIA don't like that.
Because of that want to put limitation on card and if someone get 20% more performance than mean their new series is not 30%stronger example only 10% and customers will wait, they don't like that. But performance of reference GTX980 are excellent, really excellent but only miss little to be faster than 2-3 very fast GK110 models, she is faster than Matrix Platinum example. But GTX980 SC clean floor with any GTX780Ti OC or not OC, don't even to talk about FTW or Classified models when show up. 

So it's true Surround doesnt really achieve what Eyefinity can. My last Nvidia was a gtx 295, absolutely amazing card but after that i switched to 7970 and now to crossfire 290x. Because of the silly resolution i play i need to be 100% sure about tri-monitor features. I will probably wait for next generation of cards and decide from there. At the moment there is no game i cant play at 7680x1440. Thanks so much for your opinions guys and if you have anything to share about Nvidia surround please do it: i am eager to know more.