I think that one can’t constantly change. In contrary, one needs a stable system with clear leading principles to learn something valuable.
Jumping from one teaching to another, just because you see some cool stuff on one seminar or other, is a waste of time.
It is because different teachings are not coherent with each other. Even if these teaching have common subject as aikido, the body conditioning from one teaching will contradict the body conditioning from other teaching.
But even more important is that everyone needs different teaching at his particular level. It means that only his teacher can adjust such approach – seminars are not designed for that. If you believe that your ‘once a year seminar’ will change somebody you must be very na´ve. For real change they will have to change whole pedagogical approach, change all their values and it can’t be done lightly.
Such change can be done only if a teacher strikes right to the heart of student, and a student is ready to leave/throw out everything he learned so far. Such situation is rather exceptional.