I'm in process of selling Titan; I don't really want to take the cooler off now. But that would be interesting to see indeed. I'd say considering that both are essentially the same chip with same TDP, we'd definitely see temps improvements on Titan with ACX. If only NVidia allowed custom air cooled Titans. Sigh.
Thanks. Well, I had 120Hz 1080p monitor before U2711. 1440p is almost twice the pixel count, my take would be 40-60% faster card to keep the same FPS levels @ 1440p compared to 1080.