I went with the Classified 780, ordered it yesterday. And to be clear, I had no bias - I had this same dilemma, and possibly would have bought an R9 2 days ago if they were in stock at Newegg.
Here was my reasoning:
$30 more for the Classified, call that ballpark enough. Not going to let $30 decide. (That was yesterday, for some reason, Classified is back up to $700 today)
Same or better performance on the Classified. Can't find any direct comparisons, but if you look where the Classified benches at against Titans, and then look at where the R9 is, you can see that it is generally a close call.
Way better cooling, acoustics & power usage on the Classified. Not even close here.
The Classified OC's significantly better than the R9 does *right now*. This could change in another month when there are better cooling solutions available for the R9. But best case scenario and it will still use more power, which translates to more heat - more heat needs cooling, cooling makes noise... so those aspects might improve, but wont be close to Classified numbers. So acoustics, power & heat won't leave from advantage Classified.
I am paranoid about "new card driver problems". Nothing to back this up, but its been a problem in the past - for both brands - ... just trying to avoid it.
EDIT - the 780Ti was announced @ $700. Personally, that's too big a difference to justify the performance increase I would expect.