I fish most of the time with a 2 handed rod and as such they have a built in fighting butt with the lower handle. Come in quite handy when fighting a 15 pound pissed off steelhead. Not only as a point of leverage with stuck under your belly (yes, I said under the belly, if you seen mine you would understand) but also holding it with the lower casting hand. Holding on to the lower handle works very well with the rod low and parrallel to the water during the fight.
"The reason you have a good vision is you're standing on the shoulders of giants." ~ Andy Batcho