Let me say, if you like heroines, watch it! I liked this anime because it was one like I have never seen. I've watched Sailor moon and Powerpuff girls z(and afterwords I started watching Sailor Moon Crystal), but this one stuck out to me. I honestly don't know why exactly, but maybe because they're basically powerless without each other. They can't even transform by themselves. In Sailor moon, usually not all the sailors are present. In powerpuff girls z, They can kind of survive by themselves, but are still stronger together. Perhaps it's because there's only two people. In the other animes, there were more people. Perhaps it's becausetheir powers are more associative with each other thus making a better team. If you notice in the other animes, they work side by side, but don't seem very connected.
P.S. I tried making this without spoilers, I'm sorry if I did.