Kihon vs. ki-no-nagare
The Iwama tradition of Aikido puts a lot of emphasis on strong kihon work (static form) with an almost equal weight between taijutsu (empty-handed techniques) and bukiwaza (weapon techniques using jo and bokken) as well as the relation between the two (riai). In the dojo where I study, we generally only move to ki-no-nagare (flowing form) in the last twenty minutes or so of the class.
While the techniques studied at the Aikikai Hombu dojo in Tokyo were almost exactly the same as the ones I studied in Amsterdam, most of the work at Hombu was in ki-no-nagare. Only some of the beginners’ classes would focus on kihon work for some significant part of the lesson.
This forced me to adapt and try and grasp the techniques studied as fast as possible to make them work in a flowing form. This was an interesting challenge and a good test to determine whether all the kihon work I had done so far was actually effective and if all those techniques were ingrained in my muscle memory.
The case of Irimi Nage
I would say it was overall, with the exception of some techniques like irimi nage. The way I learned irime nage so far is the direct version: upon entering, one immediately grabs the collar and places the back of uke against one’s own chest. There can then be a throw right away or after one or more rotations but uke is always kept close. Check out this video of Morihiro Saito’s irimi nage to visualize what I mean. In the version I observed at Hombu, before the irimi (entering) motion, uke is generally slammed to the floor with a quick turn and direction from nage. After that, uke naturally wants to get up and this is when the final throw is applied (again it can be after rotating a few times). This video of Christian Tissier shows the latter version I described.
My experience at Hombu Dojo confirmed my intuition that, although there are a wide range of aikido flavours, the core is the same everywhere and one can easily adapt when confronted to different conditions, be it new technique variations or ukes with other aikido backgrounds.