Thanks for the welcome, all, as well as the tips, CeramicChef!
Stuff I've figured out on my own:
-Grill surface never gets hot enough to get the wood chips smoking right.
-Water pan will become a drip pan, and I may reinject some of those drippings, possibly, provided they don't get scorched.
-Lump is king, and rings aren't necessary. Definitely producing some quantity of ash. The ring caused some dips in temp as the burn spread around. It did help keep from gaining too much temp, but I will learn to manage temps better over time.
Otherwise, a success for a first attempt. Learning how to balance airflow is definitely a combo science/art task.
I actually smoked two butts of different sizes and pulled the first off early because it was done, maybe slightly overdone. The second butt was ready about an hour later. The bark was just as I was hoping, not too crunchy, but not too soft. The meat was a bit dry, so reinjecting drippings or maybe some apple juice or cider vinegar would help. I think that was mostly due to some temp spikes.
All in all, I'm already obsessed. :-)