So, here's something I noticed with the pop-under windows: they're much easier to miss than the old way -- if (pleasantly) less disruptive. I made the mistake of resizing a chat window to be somewhat larger tonight, without moving it from its starting position. When I closed it, I realized that my poor colleague had picked up the eight or ten chats that I'd missed while working on the first chat. Luckily I wasn't on solo, and of course I thought all the background pinging I heard was just coming from my colleague's computer.
I wonder if there's some kind of happy medium of disruption between pop-up and pop-under; or if the pop-under positioning could be made smart enough to ensure some minimum visibility?
-dre.