Training for your black belt seems a world away when you first start out in martial arts, everybody's target is to be a black belt, now you know how difficult it really is and your training notches up a gear.
I personally have travelled many miles training under different clubs & instructors trying to be a better martial artist to improve my skills. No one instructor has all the skills needed to be the ultimate black belt instructor and after training at all the Bushido clubs around the country its interesting learning different skills & techniques from all of black belts in the academy.
I personally enjoy Ju-jitsu due to its variety of techniques and its continuing development and diversity. being biased I do believe that Ju-jitsu is one of the best martial arts there is to learn and training with different instructors in readiness for your black belt is the best way to present a great grading.