Let me try this one on you. If you think that Aikido is a dance then maybe you need to look at "your" ukemi and your uke. Here is what I mean: Boxing would be a dance if neither partiner tried to hit the other. Same in Aikido. If you do not give a good clean comitted attack you are not helping Nagi. Likewise if your Uke does not attack you to the point that if you don't move you will get hit. Then he/she is not doing you any favors either. This is how you can answer your question about the effectiveness of Aikido. It answered mine.
I have two people who I trust undoutedly and on a regular basis we will "test" our ability in regard to Aikido. I say our ability because we have seen that Aikido works when done correctly. The question we try to answer is "am I doing it correctly"?
Aikido is a cooperative effort between two partners. However, if one partener don't do his/her job you will not have anything to blend with or to follow.