Personally, I love this manga. It might not be for everyone, but it is so funny to me. All the demons so far are super distinct, and I love all of them. I love Gusion! I don't know if it will get repetitive, but so far I absolutely love it. I found chapter 13 especially funny so far. It seems like there will be 72 potential demon waifus, so if you liked "The 100 Girlfriends Who Really, Really, Really, Really, Really Love You", you will most likely enjoy this.
It might not be for everyone, but at least give it a try.