Oops, yeah, I blame it on sleep deprivation ^^"
Anyway:
X11-750TI: 2.1MH/s / JPC-750TI: 4MH/s == 0.525
X11-780TI: 5.3MH/s / 0.525 == JPC-780TI: 10.1MH/s?

So somewhere around the 10MH/s (also tried with the hashrates for my gtx760, it seems correct)
overclocked gtx 780 only gets 7.6MH/s sooo i think it would depend on the 780Ti
My 780Ti averages 9.2-9.3MH/s on jackpot, it's an EVGA GTX 780Ti SC with ACX. I added the config to
http://cudamining.cc for reference.
I have a 780 Ti Classified running at 1241 MHz core clock and 3600 MHz memory clock; I get 9900-10050 kh/s on Jackpot and 5.5-5.7 Mh/s on x11.
for how much power? 300W?

GTX750TI only takes like 40W

MSI AB shows 50-55% power draw, so from the stock 250W TDP, I should be pulling ~125-137.5W (haven't gotten around to putting a Wattmeter on my rig to test total draw, but then I'd still have to guess on my CPU, SSD+HDD, cooling, etc. power draw). Highest power usage I've seen on EVGA PX or MSI AB is 115% back before I flashed to a custom BIOS, which would still "only" be ~275W.
Not as efficient in terms of kh/s / W, but I also didn't buy my 780 Ti Classified just to mine with ;P
It's my one card in my main, gaming, rig, and I bought it so every game would run silky smooth (and I'm certainly not disappointed on that front!)