I also just upgraded and consistently getting the same video tearing vsync/vblank issue as the others are reporting since the upgrade to 7.3.1.
I have a late 2012 27" iMac
3.4 Ghx Intel Core i7
16GB 1600 MHz DDR3
NVIDIA GeForce GTX 680MX 2048 MB
Running OS X Mavericks 10.9.2 with no plans of upgrading to Yosemite.
I'm getting the video issue in 4D and or Panorama. It doesn't matter if it's in Low or Ultra graphics with/without smoke sun flares etc. It does seem to be worse when there is a lot of fast movement. Sitting still on the ground stationary there is less of an issue. Windowed or Full screen doesn't matter. I was in 2560 x 1440, then switched down to 1600 x 900 and the problem still exists. The issue is most noticeable in a horizontal band extending from the left edge of the screen to the right edge, roughly 25mm in height just above the heli blades. Hope this helps.
Thanks,
Greg Huntoon
Muskegon, MI USA