All the previous Ple Ple Pleiades specials were extremely outlandish as far as story was concerned, but offered some insight into lesser developed characters.
This is the exact opposite, it's much closer to the main series in tone and setting, but provides little new information, if any at all. Not even how Clementine got resurrected. Her character was pretty popular with a lot of people though, so there was probably a demand for this.
If you're a fan of Clem or the Pleiades, it's a fun diversion, and it'd certainly be interesting if it became relevant to the anime canon in the future.