I ran into a weird issue trying the Titan kernel on my GTX670. It was reporting almost 400khash, but every share was being invalidated by the CPU, besides otherwise acting fairly normally. Maybe there's an improvement to be made somewhere that could let Kepler achieve these kinds of khash rates.

For anyone looking for a config for their GTX670, I'm at 180 khash with these settings. If someone has something better, I'm all ears.
-i 1 -l K98x2 -C 2 -m 1