Well. After installing the 15.8.0.5 driver and rebooting, my Series 9 worked great for a few hours. Thought everything was fixed... but...you can tell where this is headed. Started getting dropouts again. Tried it today, and continued getting the same disconnects.
Not wanting to suffer endlessly, I ordered a $12.99 Panda Wireless N micro USB adapter from Amazon. Got it in one day. Plugged it in, it automatically configured in seconds, and I am watching videos online. Been great for the last couple hours, but I'll need a longer test to be sure. Maybe someday Intel or Samsung will fix this travesty of a wifi card. But it sure seems like they have their third string working the problem.