Great thread to get going, gums, and that's a great episode of America's Test Kitchen (damned shame that they dropped that lid on the handle so bad, though!-- that lid is really cratered around the handle).
I've done a few turkeys over the years, and here are some highlights of what I've learned:
1. I've squeezed a 19lb bird on the kettle, but I think the 12-14ers fit better and taste better.
2. Thawing a frozen bird takes at least twice as long as everyone says it will. Buying fresh is a lot less hassle.
3. If you're flexible with your timing, a great day to buy a fresh turkey is the day after Thanksgiving. My wife is a nurse and often has to work on Thanksgiving, and the years where we've delayed dinner until later in the weekend have been times when we got our bird for next to nothing.
4. Brining works really well, though that ATK video has me thinking about trying a dry brine this year. Having a more moist bird is great, but I think the real benefit of brining is the way in which the salt penetrates all the way to the center of the meat.
5. Totally my opinion, but I think turkeys work way better on the kettle than the WSM. It's too hard to get the WSM up to a temp that will crisp up the skin, and you can put some smoke on your bird in the kettle as well.