Jeff - I did two 4 lb chickens on my Weber kettle with Rotisserie last weekend. If I had my cell phone in the house I would post some pics.
I cooked the chickens at about 275 and took them to about 300 right at the end. It took just over three hours.
Like Kevin said, if you're going to be cooking at 300 - 350, I'd say less time - maybe 2 - 2.5 hours.
I pulled the chicken from the bone and chopped it for sandwiches for an office luncheon.
One thing - I used one charcoal holder (not a charcoal lighter - but the little half moon shaped sheet metal charcoal holders) full of charcoal and a couple of chunks of pecan. I filled the charcoal holder almost full, then added about half-dozen lit briquettes and the pecan. That came up to temp pretty quick and I closed the bottom vent down to about 1/3rd open to hold that temp.
It was my first time to use the rotisserie on my kettle, but that is going to be my go-to way to cook whole chickens and pork loin roasts.
Pat