this mangaka is on par with Gosho Aoyama (detective conan), and Shinobu Kaitani (liar game) in making detective-like manga than need brains to formulate. i think this mangaka is one of the first in making 'hard' detective manga, and i'm thankful for paving a way for other mangaka to make challenging manga.
however, this is quite old manga, thus the art is not very stellar. especially the first several volumes the proportion of the characters are off and the art can be a bit crude. however the mystery itself is not affected, thus if you are ok with wonky art for great plot, this is for you.
another thing to point at, this manga is quite different from detective conan, is that the cases are not as diverse as detective conan. in dc, there are quite a few other case like robbery, lost items, kidnapping and such, but detective kindaichi are exclusively murder cases, and all but one are serial murder cases. most cases are very tragic with you will sympathizing the murderers, and most importantly - more than half of the murderers will commit harakiri ( stabbing themselves in the stomach) after they done the deeds because by and large they are good people, but fall from grace due to the people they murdered and they feel they do not deserve to live after such things they do.
and to anyone who want pure logic from this manga, you will not get it as i notice quite a few 'accidents' that led to kindaichi find the perpetrator. add with the aid of videos, sometimes it can be quite too convenient.
you will also notice quite a few of kindaichi's own classmates are murderers, and such high percentage of killers in one school are too illogical for some readers. however, it does make good stories.
but all in all, this manga do have quite high drama and suspense ratio more than detective conan, so even if you dont care about detective stuff, the misery of the characters here will surely bring you to joy.