I got an Intensity Shuttle and a Decklink HD Extreme 3D+ both working on a P67. I wasn’t really satisfied with the Shuttle, so I’m trying out the Decklink right now.
I posted a very length analysis of my experience with the Shuttle on Amazon:
https://www.amazon.com/review/R91N3Z9TYUWEE/ref=cm_cr_rdp_perm
Since the Z68 is essentially the new P67, it should work out for you.
The Decklink seems much more stable than the Shuttle, but I haven’t yet got it working 100%. It would seem that my 4x Raid0 can’t handle the 10bit RGB mode and drops frames. I wanted to try 1080p60 in 10bit RGB via different capture software, but that mode isn’t exposed for other software it seems.