Lord help me, this show, I love it so. The characters are likeable, the Neuroi designs are cool, and the friendships have a bit of an Azumanga-ish feel to them. Still, I have to ask myself if the fanservice isn't going too far. Although the official same-day streaming sub is nice.
Gate Keepers 21 does much better than watching the original series
There is no way they could compare other than having the same name