You seem to be comparing overclocked (factory or otherwise) 1070s and 1080s to stock/reference 1070 Ti. A 1070 Ti has 27% more cores than a 1070, for only 12.5% more money (based on MSRP). You may be able to overclock a non reference 1070 to overcome that deficit, but I don't see what's stopping you from overclocking a non reference 1070 Ti to similar clock speeds, so the 27% core advantage is still there so you're still getting better performance per dollar than with the 1070.
A 1080 costs 11% more than a 1070 Ti (based on MSRP, $500 vs $450) for 5% more cores and pretty much the same core clock speed. 5% is pretty minimal. You keep going on about these non reference 1080s being faster, but there will be equivalent non reference 1070 Tis to compete. Like I said, the only significant advantage the 1080 has over the 1070 Ti is VRAM speed (which is directly proportional to memory bandwidth; they both have the same bus width). It remains to be seen how much difference that makes.
Let's quickly nip in the bud, by the time we're done the forum and comment section would be complete scam over an argue about releasing a refreshed graphic card with twenty-five percent more cuda cores, base clock of the GTX 1080, boost clock and same vram of GTX 1070.If you're a new buyer, the only thing GTX 1070 ti has going it is getting at ten to fifteenth frames per second over GTX 1070 with fifty dollar increase; however,if already a GTX 1070, it isn't really to get excited about unless you've a step-up program because swapping a 1070 for a ti version is like swapping AMD 7850 for 660 ti in 2012. Personally, I'll wait for the reviews to post before purchasing a graphic card. Instead of refreshing a GTX 1070, a compromise of GTX 1080, to compete with Vega, just drop the price of a GTX 1080 by fifty dollars and just scratch the GTX 1070 ti existence? Well, I don't know about you but I'm content with a 1080 on sale.