I don't really have anything complicated to say, this manga is just really interesting.
I think that the characters in general are pretty good, even the one-off side characters that are just destined to die. I don't have a problem with any of them, and that's something that's really rare.
It's also really good that Spica isn't some otherworldly being that can solve the cased without problem. Even if she has her power, it's not like she's immortal or omnipotent. She's prone to recklessness, and could easily be caught off-guard if not careful. She even got tied up and locked away at one point.
The only thing I would complain about is the pacing. Imo the cases get solved a little too quickly for me to get really invested into the murder cases, but I think that's more of a nitpick than anything. I was still interested in the mystery aspect of it, but I do think that most of the time, there's isn't that much suspense.
I would recommend it.