Here's an interesting hypothetical: how much can a terribad ending ruin an otherwise watchable 51 episode series?
I'm not about to waste a five-dollar reviewer word like "captivating" on the narrative, but at the same time I can't say I was bored. There is a somewhat shounen-esque theme of powering up throughout the series, except that in this show, the heroines are powering up their ACTING. Of course the premise is ridiculous, but it works to a surprising degree... up until that ending.
At that point, all the build up over the first 45 or so episodes is squandered. The absurd progression of acting skillz reaches its apex when the two heroines act out the four elements to prepare for the ULTIMATE play. Yes, really. Do you really need to see someone acting out "Water?" Don't even get me started on the bullshit spiritual nakey time that sums up the series' overarching romance.
But there's only so much I can deride a series that, for what it's worth, kept me watching till the end. Overall, I think the answer to my own question is: if the rest of the show is entertaining, I can only fault the series about half a point. Whatever that means.