Couldn't find a thread for this, just finished the most recent update (chapter 63 on Batoto) and was hoping to find some comments, so since there aren't any I'm making my own thread.
The manga is pretty good, although I did find some minor plot holes, but it's quite enjoyable. Definitely worth to check out. The premise is that a certain group of people are stranded on an otherwise uninhabited island, each given a certain type of grenade with the objective to collect 8 "chips" (including one's own) from other people by killing them, which is the only way to get off the island. This concept is very similar to the online game of the same name, which the main character has played a lot and is a world ranking player in, so he has a certain advantage over other players by knowing a lot about the strategies and different types of bombs/grenades.
The fun comes in when the reason behind the people being there in the first place gets revealed, as well as who put them there and for what purpose. Overall, a good story with good art, fairly decent characters (sometimes a bit too stereotypical, but otherwise alright), and a fair amount of attempted exhibition of human psychology mixed with some gore, but not too excessive. A much, much better "Gantz" (like, way better, and not very close to it, but that comparison still applies to an extent). Give it a try and let me know what you think of it. Last update was in November so I'm HOPING it is still being released fairly continuously.
Edit: minor gripe here: the main character on the cover has dark brown hair, but it's left white in the manga. He looks like Furuichi from Beelzebub like this though, which I like.