I have seen many debate on this topic in other forums. And though they usually never come to a conclusion, I have my own conclusion.

#1: it's all a mather of how experienced you are at a specific martial art. All martial arts are good if you have trained it long enough. and some martial arts need more time than other to grow into something worth harvesting. The thing here is that what takes longer time to grow usualy give you more quality.

#2: what enemy you are facing is another variable. rock takes scissor, scissor takes paper and paper takes stone. There will never be such thing as a perfect martial art system. The thing here is that you can ether train for many diffrent opponents and be medioker, or specialize at one specific opponent and be great.

of what I have heard about Aikido, when it comes to point #1 it falls in the category of martial arts that need much time to grow.
As for point #2 I can only speculate.

What exactly are you looking for in a martial art?
And what do you mean by "if it works"?
It's a silly question because I kind of know what you mean. but point #2 makes it important to specify.