One great thing going is that there is maybe 1 frame delay between the viewer and the BMD output to an external monitor (on my ultra studio express). Before this update it seemed like 3-5 frames off. It was quite distracting, and you had to send audio out via HDMI or SDI and monitor it on that end. That of course is a pain because you have to switch over your whole system audio with BMD devices and route it through the monitor or something. Then the audio is off on your computer display. I send computer audio and BMD audio to the same speakers, so now I can leave it on system audio and control monitoring volume with F11 and F12 on the keyboard. Much more convenient than an external mixer.
I plunged ahead an updated and then realized it was a major upgrade as it had to update all libraries. After awhile it finished and looks fine, to my relief. My first impression is that it does a better job handling my 35 MBs, H.264 60 fps files, when editing. They look better in playback mode and timeline seems snappier.
Same issues with the AJA T-tap, but no difference with 10.2. I've started using the HDMI output on the Mac Pro instead. Perfectly in sync and no switching audio outputs. Yeah, I know it's not baseband video, or whatever, but I can't tell the difference.