I myself don' t practice TSKSR. But a lot of people around me do, because my aikido teacher also teaches it.
The swordwork we do is what Christian Tissier teaches, who was student of Inaba Minoru sensei. Plus we do some forms of aiki ken also.
But TSKSR inspires me a lot.
Mostly because it made me understand how important precise movements, postures and use of the body are. Precisely working on one's own body: This is very similar to what Endo sensei teaches. First tuning and building one's own body. Not relying on what uke does but creating connection or the relationsship from within ones own body.
And it teaches how "the ki things" can be learned on a bodily, down to earth way. No esotericism but just moving your shoulder a little bit here, your toe a little bit there - et voilà. This also relates to the teachings of Tissier: First work on your body, on your structure, on your correct movement.
So it is not certain forms or waza of TSKSR which are interesting to me. There is no maki uchi in aikido, the hanmi is different and so on. But the way of how to use one's body is interesting and helpfull to me.
Interesting points, Carsten.
My own feeling is that it is indeed very useful to study a varied range of other disciplines, but that certain ways of using the sword lend themselves more or less well to particular approaches to aikido. For instance, most teachers in the lineage of Yamaguchi Sensei practise the kesagiri cutting style (and a few teach more advanced katas) from Kashima Shinryu, rather than the "Aikiken" of Saito Sensei. Examples of this are Tissier Sensei, Gleason Sensei and Yasuno Sensei (though an interesting exception is Yamashima Sensei who, although profoundly influenced by Yamaguchi, practises Yagyu Shinkage-ryu swordwork). Similarly, most people who follow Chiba Sensei also practise his sword katas, as the way of moving the body is the same.
As I have been trying to follow Kanetsuka Sensei's developing aikido over the years, I have found the body movements involved in kesagiri more and more helpful to me, as they feel very consistent with the way he makes the connection with his partner. At the same time, I find it increasingly difficult to do the more tightly-controlled Saito-style swordwork to my own satisfaction, as it feels much less natural to me, and doesn't "fit" very comfortably with the way I want to take my aikido practice.
I wonder whether your liking for TSKSR is precisely because it is in a fundamental way separate from aikido - it wasn't developed in order to inform a particular way of doing aikido technique, so in a sense you can take what you like from it. I would be interested in your thoughts - do you find there are any movements in TSKSR which you feel are incompatible for any reason with the way you understand aikido? Do you think it would be difficult to practise both that way and your teacher's kesagiri cutting?