Ribs turned out great. A couple of things:
I followed exactly what the directions said, but I think 3 hours pre-saucing is too much. When I removed the ribs to put the sauce on them, the rack damned near fell apart (ok, it actually, really fell apart and a good hunk fell into the charcoal basket).
After washing the ashes off (

), I sauced it but couldn't get the hook to hold well. So I put the grate in and laid the ribs on that for 5 minutes just to let the sauce take hold.
I'm not sure I did anything wrong - vent was at 1/4 open, times were followed - but it was also hotter than hell here today; I don't know if that matters.
Anyway, made it through my first try relatively unscathed with some damned good ribs. I think next time I'll cut back to 2.5 hours before adding the sauce just so I can get them out of the barrel in one piece.