Personally, I think of HSOTD as one of the most disappointing animes I've seen in some time.
The actual premise itself is fairly interesting, how would Japanese high school students fair in a zombie apocalypse? It's a grim, gritty take on the actual horror and stress that would place on someone.
Unfortunately, it's ALL undermined by the gratuitous fanservice. It's trying to eat it's cake and have it, too. It has bits of humor juxtaposed with serious melodrama, and it just never jells. At all.
Now don't get me wrong, I'm not opposed to fanservice. Quite the contrary, one of my FAVORITE recent animes is all about fanservice:
The difference being, THAT show is a self-aware comedy, and HSOTD is trying to be serious. Except the fanservice is so all-consuming, I CAN'T take the show seriously. We get people mourning the dead, interrupted by panty-shots, and endless jiggling. Hell, that doctor character seems to exist ONLY for the fanservice. Admittedly, I've only seen up to the 8th or 9th episode, but I can't remember a single damn thing she actually DID, other than drive a car, and create boners.
In summation, I view HSOTD as a large pile of wasted potential.