Greetings Guys,
First of all, as a disclaimer, I am working in Shimano S.E.A. as a rod designer, and Caranx was one of the models I was working on, so do take what I say with a pinch of salt due to my affiliation.
Anyway, the long butt design rationale has been going on and on through several forums and now that Jon has brought it to this particuliar one, I guess I will do the explaination here again for the benefit of those who own the rod.
I've been often asked why the LC, DM and SM have such long butts before, and no, the answer is not bcos I am big sized
So heres to explain the rationale of this new pop rod design concept....
The benefits of the longer butt are twofold, firstly and obviously, it will be easier to cast and pop, which is what alot of us have to keep doing as fish strikes are not so frequent as we would like and alot of casting is usually involved between strikes. For imparting popper action, u can tuck the rod under ur armpits to generate bigger bloops, or you can simply take advantage of the longer butt to work the chugger while it is in the belt(if you are tired)
Secondly and more importantly is for the hookup and fight. When you first hook up, u need to set the hooks properly b4 transferring the rod to the belt, the long butt allows u to tuck the rod right past the armpits to give you much more positive hooksetting power.
Caranx Kaibutsu was designed for use with low mount belts, i.e belts that sit on the thigh, not those that sit above the "crotch" region.
For fighting, try pulling on the rod with a lower mount belt, vs pulling conventional shorter butt rods with the usual high mount belt....measure the pressure on the angler vs the force applied on the fish and you will know why the butt is longer for use with low mounts. Alot of times with a high mount belt, the angler seems to put alot of force into the fight, but by the bending curve of the rod, you can see the translation of force to the fishes end is only very limited....
High mount belts originated from jigging and were simply doubled for use when popping. They are great for jigging to increase the angle between the line and the rod to utilise the stiffer lower end of the blank as the fight is down deep, but try that with popping rods with fish fighting closer to the surface and you will likely face a tip over feeling when you start utilising above 10kg of drag due to the length of the rod working against u, not with you; this time the leverage is working against you due to the rod length and the above mentioned angle has to be reduced for u to fully utilise the power of the rod on the fish.
Anyway, the 3 heavier rods with the long butts are specifically designed to be used on lower mount belts to avoid that kind of dangerous situation whilst still being able to apply above 10kg of drag easily throughout, and this has been pre-tested by many average sized asian anglers, not just big sized ones. Using a low mount with adequate butt length allows you to keep your knees bent and lean back rather than crouch forward when locked up.
To sum it up, if you are an angler who likes and uses only high mount belts only, u will find it hard to "tame" these rods as the forgrips will be out too far and probably Caranx is not the rod for you; you'd be better off sticking with other brands with a more conventional design. If you do own and fish a low mount belt and tend to fight fish in a more aggressive manner in a "lock and sock it them manner", then Caranx will be suitable for you.
It is a new design concept in popping, some might not understand the purpose of the design, but I hope you will give it a try urself to experience the benefits of using this design concept.
Regards
Daniel
Not just a surf and jig fisherman 
I think the idea is to have more leverage for casting, especially in the LP, PI and LC. Also it allows you to use medium to heavy standup gimbal setups with the rods, like you said, fishing with a lower gimbal setup. This way you're not using you back so much. Bend you knees to lift the rod.
