So looking at the 2 arts being practiced we do see some differences - of course. But if these arts are basically the same thing, why do we see the differences in their applications?
A big difference is simply the attitude or intent of the practice. Sport changes the intent dramatically. As Karl Geis said "Once you put a trophy on the line, people start breaking arms." The same goes for Judo and Aikido. Judo practice is aiming for soft, but change the intent, or goal to VICTORY, and skill is replaced with power, softness is replaced with hardness, timing is replaced with speed.
Needless to say, I feel sport damages good budo. Rules have to be developed - then they are exploited. Loop holes found...and plugged and the whole game drifts farther and farther away from good self defense.
So yesterday I demonstrated what I believe was the founder's intent or goal of Judo. Today we see it's modern sport reality.
Typically Aikido people don't compete. Some Tomiki folks are the exception. Here is an example.
Notice how changing the INTENT changes the result. If we intend to win at all costs, both Judoka and Aikidoka throw out softness and harmony in order to score points.
So to go back to my original point - Aiki and Ju are pretty much the same thing. We can see during training in kata the results are similar. In sport competition the results are similar. While technically the arts are similar the primary difference is simply the motivation of the sportsmen - their intent changes everything.
Important lesson we can take from budo and apply to life - intent changes results.