Hello community,
It's been a while since I have posted here but this forum has always been the most helpful. My question is in the title and I ask this because I play a lot of recent games but never do I see both cards being fully utilized. My FPS do increase slightly when switching from single card to SLI, but it's nothing astronomical. So give me your opinion and also, if maybe I have some settings wrong, please share with me.
My setup:
EVGA 980Ti x2
i7 3770k oc @4.5
ASUS Maximus V Extreme
16 gig RAM @2133

I would think so, although the new GTX 1xxx Cards are only supporting 2-Way SLI it is still around.
Most games that support SLI are still supporting it. Some new games are also supporting it.
Though not all games support SLI and some games you need to disable SLI to play I still think it is worth it.
With having Two EVGA 980Ti Cards now you can wait for the next generation card to come out if you want to move down to a single card.
 

It would definitely be worth it if you were into 144hz or 4K gaming.  1080p gaming not so much.  As mentioned above it would probably be best to keep the 980ti's for now and upgrade to the 11xx series in Q2 2017(?) if you decide to.  I would not recommend upgrading to a 1080 SLI from a 980ti SLI.  Yes, there would be a large difference, but its not really needed.  

Definitely still relevant. 

Yup, still relevant. I went to a 2K monitor and when I tried to play Black Flag and Unity fps sucked on one card so I picked up a second 980 Ti and fixed my fps by more than double on both titles.

Would it still be recommended to grab a 2nd 980TI for SLI at this point in the game from the B-stock  if running 1440P? Or wait until the "possible" 1080ti? 

2 980ti's = 1 Titanxp
 

ordained87
Would it still be recommended to grab a 2nd 980TI for SLI at this point in the game from the B-stock  if running 1440P? Or wait until the "possible" 1080ti? 

You could, but I have seen GTX980Ti sell for 300$ or a little less and they had much more than a year warranty left on them,  the RX cards only have one year warranty.
Look around on the big computer forums for sale sections
 
Or wait a little while for EVGA to have a sale, seen new cards sell for nearly the same price as the B-stock. But B-stock does have sales too.....

Definitely still relevant.

chiptouz
Definitely still relevant depending on the games that you play.

FTFY.