The first two episodes are essentially pure fanservice, which drags the score down for me. If you like fanservice, you will most certainly enjoy them more than I did. If you're looking more for something that hits the "regular" pace of this show, the third OVA gets back into that, starting a story centering around the academy kids. As it ends partway through telling the story, the 4th OVA will doubtlessly continue, and perhaps even on to the 5th. This OVA isn't really anything special and I doubt that it will significantly change the direction of the plot, but if you really like the show, it's worthwatching.