It seems like the aiki taiso you are talking about are similar to the Kihon Dhosa that we have in Yoshinkan Aikido.
I am fairly new to Aikido (5 and a bit months!!) and have found these movements very beneficial in understanding the foundations of the few techniques I have learnt. When being shown a technique it helps a lot when Sensei, or my Sempai say this is like XXX we do in the kihon dhosa!! It gels the basics to the techniques very well, and at my low level of achievment that is worth its weight in gold in helping me to improve!!