Are 2 GTX 1080's SLI Better?

[Zedahr]

I have a custom desktop computer delivered to me in December 2014 and
while I presently have it at the maker's shop for a refill of coolant, was wondering if now is a good time to upgrade my gpu's to GTX 1080's?
My present GPU's are 2 GTX TITAN Black 6GB GDDR5 3D Vision Surround w/phys x in SLI. Can I 4K with these new 1080's and will these also support VR? I have an X99, 8 core chip set in the 22nm Haswell class, LGA 2011 v3 with an i7-5960X 8 core CPU.

Thanks for any advice.
.

 

[EndlessWaves]

Kitguru reviewed them against a Titan Z which is the single card version of your setup with similar but slightly slower performance:
http://www.kitguru.net/components/graphic-cards/zardon/msi-gtx-1080-gaming-x-8g-rgb-sli-review/

It looks like the average performance at 3840x2160 is around 50-100% faster. So not a huge amount, but noticeable if you want to be on the bleeding edge and your current setup can't keep up.

 

[Zedahr]

Kitguru reviewed them against a Titan Z which is the single card version of your setup with similar but slightly slower performance:
http://www.kitguru.net/components/graphic-cards/zardon/msi-gtx-1080-gaming-x-8g-rgb-sli-review/

It looks like the average performance at 3840x2160 is around 50-100% faster. So not a huge amount, but noticeable if you want to be on the bleeding edge and your current setup can't keep up.

Thanks so much EndlessWaves for your reply and information. I agree. Not much faster. I'll probably wait until I also need a new chip set to upgrade my cpu then purchase a top line gpu then. AR will most likely be more perfected also, besides I just can't wrap my mind around having a tv screen on my face just yet.