Just tested 980Ti SLI. Latency is totally gone now compared to .5 SDK however there is a major caveat, SLI performance is not great at all, each card is at about 60% utilisation. There may be a performance increase but I'm not seeing it. Planet side with everything maxed out I'm getting fairly consistent 75fps with occasional hitching. It is not particularly stable either, crashing after just a few minutes.
I'm really optimistic though as prior to 1.3 SLI was not usable for me. Now it is absolutely fine latency wise, just needs to have some optimization. I'm really happy that SLI will be suitable for VR, I had doubts before.