I also voted "critically valuable" indeed.
Seminars are like experiencing legendary performers live. We participate in kind of a creative seance of aikido. Not every seminar is a revelation, but I find that I learn a lot also from seminars where the teachers are not the legendary ones.
I guess that it has something to do with the melting pot of it.
Competing sports have competitions as their festivities, and aikido has its seminars. It would be much poorer without them, and I would be much less inspired.
PS: Only three more days until our seminar with Tamura sensei, and I just can't wait. If you have been to one of his seminars, you know the feeling - if not, hurry to the next one within your reach!
I assure you that when you have experienced it, you will also vote "critically valuable"