If it is bone-in, figure 1 pound per person, boneless, figure 3/4 per person, so around 7 pounds is good, Serve lots of potatoes to the big eaters.
I have had Prime Rib cooked in a showtime rotisserie, it was not bad.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
Whip It Off, Chambers!
"perhaps...but then again...maybe not..."