To my surprise, My-Otome 0~S.ifr has a coherent plot. I was expecting it to be pure eye candy like My-Otome Zwei, featuring Arika's mom thrashing random deadbeats. Instead, the first two episodes make an honest effort at reconciling the HiME and Otome series—bridging the gap by explaining what happened in the hundreds of years between the two shows.
I don't really miss any of the regular HiME/Otome cast yet, so I'm going to take that as a sign that the My-HiME franchise may be able to live on Gundam-style, adding new installments every so often—at least for a little while. Then again, to some extent this is probably because I feel as if I already know the 0~S.ifr characters; My-Otome already revealed what happens to them. I already like Arika's mom better than Arika, but I can't say the same for Nina's mom.
However, I do sorely miss Kajiura Yuki's music in My-Otome 0~S.ifr. This is not to say that the new music is bad, but it does sound more conventional. It's as if the Sifr OVA has a different soul than the previous incarnations. The change hasn't critically hurt the show, but I really hope future My-HiME projects will have Kajiura Yuki compositions supporting them.