I am most familiar with these than with any other Aikido style, as I trained for many years in both.
As far as I'm aware, Kenji Tomiki was a student of Ueshiba. Tomiki
Aikido, as a style offers more resistance, and I have found it more practical in real life confrontations. I also found this style relatively quick to pick up, although I don't know why.
, on the other hand, is very similar to actual Ju-jitsu, in that it employs many kicks and strikes as well as joint locks. Together, these two styles worked well for me, and seemed to compliment each other.
I also studied the Korean Hapkido
style, which was very similar to Aiki-Jujitsu. It gets kind of confusing sometimes to find the point where one style ends and another begins. I think all these styles compliment each other well.
, I think, is traditional
Aikido in its purest form. Last year I joined the local Aikikai club (but had to leave due to serious health problems
), and found it very difficult compared to the Tomiki style.
Hapkido almost has all the elements of Tomiki Aikido and Aiki-Jujitsu, with the addition of grappling.
This probably doesn't help you much!