I've pulled these numbers for most of these cards from from my GTX Titan review. They should suffice for a quick comparison.
Although the GTX 780 has the same peak power rating as the Titan, our review card tends to draw a little less power than our Titan, overall. That's not a bad place to be, in the grand scheme of things.
Noise levels and GPU temperatures
That Titan-style cooler is even quieter on the GTX 780, in part because of the 780's lower power draw. As a result, 780 is the least noisy card of the bunch under load. (They're all whisper quiet at idle.) That cooler keeps the GK110 chip right at 80° C, which is the temperature target for Boost 2.0.