I love doing rotisserie chicken on the Weber. This is my no stress method that works for me. I always dig around until I find two chickens that weigh right at 4lbs or maybe a little less. I use a little oil with my own rub and truss the chickens. I prefer brining, but this works for me either way. This is one of those times when I take out any half burned charcoal and set it aside and start up a chimey filled to the top with new Kingsford charcoal. I put a couple of small pieces of wood in the bottom of the charcoal baskets and then dump the lit charcoal evenly in the two with drip pan in the middle. Just as soon at I dump the charcoal I put the chickens on and start the rotisserie. I personally think this high initial heat helps seal the deal. I put the lid on and set the timer to 1 hr and 20 minutes and leave it alone. When the timer goes off, I check the temp in the thigh and that juices run clean, which it virtually does every time. I pull them off and I am done. This combination of the new Kingsford briquettes and 1hr and 20 mins works for me to the point I almost don't need to check the meat temp.
BTW - your's looks great.