Great addition to Google+, and something I personally suggested many months ago. Whether that had a difference or not I'll never know, but glad you developed it :)
Anyhow, just wanted to give you a little feedback:
I'm using a Samsung Series 5 Chromebook, and have noticed the video is very choppy. This doesn't seem to be the case with Hangouts so I wondered if you are using a different video capturing technique. I know this particular Chromebook model isn't that great with handling video, so maybe its just a hardware issue as the video preview is a lot larger than that of hangouts
Any how, maybe you can have the team can look in to this. A great start though.
cc: +Melissa Daniels