I know that the Titan wasn't marketed for this, but no one has talked about the card being able to do double precision work quite well. Not as well as a Tesla k20x, but still way better than a 680. I know that no consumer will need that feature, but it's gotta count for something, right?
Like I said in the review it has the ability to run double precision calculations. Its a gateway card for the person looking to start developing for CUDA without the spend for a Tesla.
^This would be the only reason I'd consider one. Yes, the gaming performance is great, but it completely overkill for my needs. But for the CUDA development, that's something I'd be curious to try out as a budding game developer. That being said, I'm trying to lean away from programming because I got sick of it in my last job