Adding a second 980ti is next to pointless in the dictionary mate. Honestly, SLi just doesn't work any more. I could sit here and list off all of the games where it doesn't work but there's no point, just add every game released in the past year or so. It really is a dire situation but has happened since the new "console ports" came out. They're now easier than ever to do, so even less work goes into making them work on a PC hence no AFR support whatsoever.
IMO having water is the reason why I would buy a T XP. They really sing under water.
Nvidia will not release a 1080ti until AMD have something to compete with. And that could be next year. Even if they do release it now what do you think it will cost when 1080s go up to £750+? You're looking at £900 if they launch it now IMO.
Lots of people think the 1080ti will be faster too, can't see that happening either. The 1070 is slower than the 970 was compared to the 980 and they have done this to create a clear gap between products. Why would you sell a £900 GPU when you can get £1100 for it?
I dunno man. Me? I would go Titan. They have a longer shelf life than any other GPU.