My own preference is no poles, one pole, or two poles - depends on the day of the week and what kind of mood I woke up in. :)
When you're carrying a 15-pound load, I wonder just how much weight you can actually transfer off your feet?! So, that's not a real advantage. Also, from time to time, I've found them annoying to use, and I've even felt a little silly using them with such a small pack.
The main advantages to me are just easing the shock of downhill on my knees, and the general assist to balance - as Colin Fletcher points out, a tripod is more stable than a bipod or monopod. (You'll only be a "quadripod" if you're standing still.) I've also used them, once or twice, to provide the illusion of a railing for people crossing a narrow ledge, and to jam under a kid's foot to make a foothold when he forgot to figure out how he would get down before he started up.
I'm currently using two poles, because they let me set up my tarp anywhere I choose. That might be a main reason for you to use them. You mentioned that you currently use a tent; if you're inclined to try a tarp (or Tarptent), the poles can do double duty as tent poles.