Great that you do that at your dojo, Robert. I wish my sensei were more trained that way. We would no doubt be sitting at least for short periods.
Still, I can't understand why
O-Sensei would have considered Zen to be the opposite of Aikido, as AikiTom has said. It would seem to me to be right in line with the principles of the Aiki Way.
Zen speaks of seeing life directly, with no judgement, preference or color to it.
And from what I have learned Aikido teaches basically the same. If you have some preset way you think you will deal with an opponent and you are not just open to whatever happens, you're defeated before you start!
O-Sensei even had some kind of Satori which you just don't have unless you are living your life in some kind of meditative manner.
Basically, I feel meditation ought to be part of Aikido training or at least students should be encouraged to try and incorporate it somehow. We would all be that much more *present* while training.
On an interesting note:
Steven Seagal said that Aikido didn't really start clicking for him until he started looking into the spiritual side of Aikido... Go figure...