The last two episodes of each season touch on what could be, if expanded upon, an interesting sci-fi tale of alien invasion, government conspiracies, and military hubris. The rest of the episodes are basically days-in-the-life of the witches which could be, if the interpersonal lives and feelings of the witches were explored, an interesting tale of emotional examination. Unfortunately, neither of these is the case and we're left with what is little more than a collection of non-sequitur vignettes.
For example, some of the girls share beds suggesting they are couples, yet we learn nothing about their relationships despite this strong implication. Nor do we ever learn how any of the witches feel about virtually anything at all, either meaningful or trivial. Also, there is clearly something going on behind the scenes with regard to the military and the aliens invading Earth, but we never discover the truth about that either. In fact, the first episode of the second season starts by literally killing off what the end of the first season hints at. Yes, the often commented on fan service abounds, including full nudity (though genitals are always blocked by conveniently placed objects), but the matter-of-fact way it's presented (even strangers don't give the girls a second glance) coupled with the rather plain, though competent, animation style leaves these moments practically devoid of sexuality. Even the scenes where the one witch with a penchant for fondling the other witches' breasts, including full nude scenes in the communal bath, are more light-comedy than titillation.
Ultimately, while Strike Witches isn't terrible by any means, neither does it offer any reason to recommend it.