Yeah, I got the same results from dual 680s as a Titan and the 780ti in my z820 is just a bit faster, but all 3 really comparable in real world usage, in regards to Premiere and AE. If you were using something like Resolve or Octane I might be concerned but, yeah, a regular 780 with lower power requirements seems like the sweet spot.
Any plain 780 or the ones MVC sells? I see they're like over $1000!
How about one with 3 or 4GB of memory? Maverick should see it no issues, right?