Yay, the poll!! <3
I love both songs, but I decided that my favorite of the two is definitely Ai on Gundan. Wagamama is great; it catches your attention because it's fast and powerful--it's just born to be an a-side, and it's understandable why it's the main a-side. However, I don't always like really fast songs. It's the same for Brainstorming. I can't listen to it over and over and over without feeling a little tired, which is partly why I prefer Kimi Sae in the previous double a-side and why I prefer Ai no Gundan to Wagamama. Also, I'm a lyrics person, and the lyrics to Wagamama doesn't impress me that much. Maybe it's the awkward translation, but I don't think that much got lost in the translation.
Ai no Gundan, on the other hand, sounds more musically interesting to me. I like how it sounds random the first few times you listen to it, just like many of the recent singles. The sounds more relaxing and doesn't try to be so epic, attention-grabbing, and the girls don't need to try to be so cool and fierce (which doesn't always work for me anyway). All of that plus the great choreography and PV concept makes it seem like you're watching some professional dancing in a fairy tale play, which I like a lot.