I personally liked Kazumi too, but my personal gripes about it were more than the fanservice-y outfits.
Kazumi living in the end makes literally no sense to me; it's a forced happy ending. I would've liked it better had Kazumi died in the end and Michiru's point emphazied about despite not being there anymore she'll still live on in their memory (like her grandmother).
Hijiri (I know her name is Kanna but I like calling her Hijiri)'s apparent insanity over discovering herself to be a clone advanced too quickly to the point that she started to take everything out on everyone instead of strictly the Pleiades Saints wasn't handled exactly well either imo.
I kinda also wish the minor characters as such the policewoman made more appearances and showed another side to the series in the eyes of the normals. The Soujus not having a back story either is a waste as well.
I do like Kazumi, but I know it wasn't the best spin off out there. I'm hoping if it ever gets a rewrite or an anime (which is unlikely, but I can dream), it fixes these issues (and maybe the outfits as well).