We've done this every trip and usually on a non EMH day. I usually book the first sitting or close to if possible... this puts you in the park before the gates open at 9am. Youll get escorted through an empty AK to Restaurantosaurus and seated.
The meal is buffet and its free-for-all. Although the food is OK it is the character interactions I have enjoyed the most here. Be it with my 32yo brother last Sept or my Mum and the Twins in 9/2001, we've always had a great time here.
Bonus: By booking an early PS means you can usually get out before park opening. For me, that means 2 or 3 Dinosaur rides, 1 Primeval Whirl ride before the first lot of crowds appear. And with a good breakfast in your belly, I always find it helps the hot days in AK pass all that much nicer.