If you look at the plot of this manga, it's ultimately common. If you look at the drawing, it's pathetic. If you look at the set up, it's naive. To sum up, this manga is a total failure.
Let's take a closer look at every thing:
A supposedly dead person got link to a living one. They'll both die after a certain amount of time if no one do anything. We have lots manga like this. 'Til recently, we have Bleach which is very successful, The World God Only Knows also make quite a debut. Obviously, they would be compared. Talk about bleach would take too long, so let's compare this manga and The World God Only Know.
On one hand, while the plots are relatively similar, this manga deals with dead soul of living creature of earth. It means not much to develop. What else can be there? They'll just go and deal with soul after soul until the very end. On the other hand, TWGOK deals with evil spirit from hell, which lead to a whole bunch of new possibilities. The main characters might end up bringing hell to a new life. Might as well get to heaven to seek help. That's what make a plot interesting. If the plot is common, the development is the most important aspect.
Next is the set up. A pair of pathetic boy and characterless girl will never be better than a pair of genius weirdo and a clumsy girl. Ever since the start, Kokoro is like a shadow. She doesn't have personality (obviously, she will be a sale-less idol). She doesn't play any role in soul-releasing. All she does is showing off her panties and boobs. And the pathetic guy is just like he was built 'pathetic'. Nothing more to him. In contrast, Katsuragi in TWGOK is an unique type of character. He can also be call a pathetic guy but he is interesting. He has ways too many side that attract attention. And his partner, Elsee is your run-of-the-mill clumsy girl, who is sweet and innocent. Needless to say which set up is better.
The drawing is even more of a different. While TWGOK characters all and each have an unique face which match up with their personalities (even with Tenri who has 2 characters inside), Baka to boing's Kokoro and Rie have the same fake innocent face; even the shinigami sometime looks the same. Expression wide, TWGOK is also better. Of course, art is something related to personal liking. So I wont take the argument any further.
To sum up, Baka To Boing is just an average manga in which selling point is boobs and panties. It's too far away from becoming something great. But good enough to be kind of like a side dish, a desert after you read other mangas.