Re: Relaxing Aiki vs Yoga.
In my limited experience: the feeling in your mind and body after keiko also differs depending on what kind of aikido and training you have been doing.
After a intensive class withs both "static" and flowing taijutsu I usually feel physically tired but always in a very positive mental state.
After a intensive hour of bukiwaza (suburi, awase-exercises, kumitachi/jo) I´m mentaly drained.
After a hour of only soft flowing ki no nagare practice I usally find myself in a very pleasant and energetic mode both physically and mentaly.