It's the usual maid storyline involving bondage and discipline. In the first episode, "Train Me" Nagisa has recently moved in with Matsudo and is currently in training to be a maid. It's not very hardcore compared to other BDSM hentai which involves public humiliation. Matsudo cares about his maid, but is still perverted when it comes down to disciplining Nagisa. The art is actually good even though Matsudo has purple hair which was worth a laugh and Nagisa is very nicely drawn especially in the erotic scenes. Maid in Heaven also has an opening animation which is nicely donewith a cute song.
Overall, Maid in Heaven SuperS is pretty good for maid fans, it has a good soundtrack, and most of the scenes are nicely done.