Honestly, my biggest worry in this series (aside from the fear that they'd handle the subject matter poorly) was that the author would feel forced to pair the two together. The whole point was that as much as Haruka changed, they really haven't. It's Kazuma who had to change if they wanted to find that spark their friendship had.
I think tossing out that friendship and making it a romance, just because Haruka's gender flipped... I don't know, it feels like an easy way out. It feels like he's dating his bro, now that it's socially acceptable. It's much harder for Kazuma to hold onto his original feeling when going through an emotional upheaval.
I also kind of take issue with that fact that Haruka's transition was the result of some unwanted magical disease, than anything realistic. But I think it worked out in the long run, showing how she felt wrong in her body and like she had to perform female now that she's been forced this way. It was a round about way of talking about it, but we got there.
All in all, pretty good ride so far. Two chapters left, and I hope we stick the landing.