I must admit that I don't have a lot of experience with smoked chicken, so I don't know how juicy it comes out at 165. I know that when I poach, bake, or roast to 165 internal that I just can't seem to get rid of the dryness (I know this is a bbq forum, I just thought this concept might cross over from the kitchen into the bbq world). As for the meat staying at 150 long enough, between the time it takes the chicken to go from say 148 to 150, and the time it rests, you have more than enough time at temperature to properly sterilize the meat. I've never known anyone to get sick from chicken that was cooked until the juices run clear and the sliminess is gone (which from what I can tell tends to be anything above 145).
Just my 2 cents. I'd say if your chicken stays juicy at 165, might as well cook it to 165, but you shouldn't be scared of the lower temps.