Douglas brings up some good counterpoints of visiting and training at a different dojo.
From my own experience (which will probably differ from others), I was lucky in starting at a very open dojo where training with other people was encouraged. About after a year or so of training there, I really started going around to many of the other dojo in the area as I was no longer a "member" of any one dojo. I also partook of as many seminars as I could in many different approaches to aikido. This diversity, for me at least, has proven to be beneficial in the long run as I now understand that there are plentiful ways of approaching the same principles as a student as well as being exposed to many different ways of demonstrating and/or teaching certain things.
I still stand by my feeling that many dojo/instructors/practitioners in aikido are "xenophobic," holding onto their assertion that what they do is inherently better (as in, "the way they
do it is wrong
") than others.
Of course, the way one practices will most likely be the "best" method of training for that person; if it weren't, why would one train in that method? As such, I do agree that organizations, affiliations, and styles exist due to people's thoughts that their method of teaching aikido is very much in accordance to their belief of teaching aikido in the most effective and efficient manner.
However, the "xenophobia" above more refers to practices within certain aikido cultures to insulate and, perhaps, isolate the students from other approaches of aikido. Too many times this came from a sense of insecurity of the instructor; other times, this came from the instructor not getting along with others.
Of course, if students do go "outside" their dojo to get other kinds of training, they should go back to the usual manner of training at their dojo. Fortunately for me, I feel I have the leeway where I currently train to emphasize different things -- in essence, I don't need to become a carbon copy of my teacher. As such, you may find me in the class of my main instructor doing something, for better or for worse, with a different "flavor" than what my teacher is doing. Others undoubtedly train at places where such explorations aren't as encouraged...
In any case, all of the above was taken from my own experience. As I said, I started wandering around quite early in my own aikido practice and have attended more than a few of these kinds of "cross-cultural" aikido seminars. From my own experience and from what I've seen so far, such events have been beneficial regardless of one's experience level and background...
PS: The information on the November 15th and 16th Aikido-L Seminar in Toronto will be posted here