This is the kind of manga I'd usually enjoy; insane, twisted characters, a good bit of fighting and killing, no annoying romance or lovestruck teenagers...
But I didn't enjoy Rinjin 13 Gou. It simply did not manage to live up to what I expected of a story dealing with dissociative personality disorder as a result of childhood trauma. The actions of most of the cast were, more often than not, quite inexplicable. If 'No 13' so desperately desired the death of Akai and everyone close to him, he had countless opportunities to kill them. Akai's wife is implied to have been a gang member; yet she behaves like a damsel-in-distress whenever threatened! And despite that (or perhaps because of it) manages to escape death or even the slightest injury. I understand that because this is a seinen, killing off the sole female character might be unacceptable -- but if so then she should have behaved in a way that made her repeated escapes plausible.
The portrayal of police officers as the typical ignorant incompetents was also quite silly. It would have been better to simply exclude the police investigation from the plot than to include it in such a cliche fashion. A shame because if the police pursuit had been executed properly, the plot would have become quite suspenseful.
Not to mention, the way Akai and his wife eventually escaped death was just bizarre -- and severely anticlimactic. The implication that Juuzou somehow avoided punishment for his crimes even with eye-witness evidence being present against him was also illogical. It would have been much smarter for the author to not have included that final scene where he was completely surrounded by the police; if he'd escaped without them being any the wiser, the story might still have ended on a fairly good note.
I will not give the series too low of a score, however -- for it did keep me reading until the end, and managed to incorporate some interesting ideas (which were promptly ruined by the weak execution)