So I've been binging the hell out of this for the past four or five days. It was my primary anchor while I was sick. I've made it to season four. At this point, the story is compelling enough that I'm still watching, but Liv's tendency is to be completely dominated by the brains she eats while even though who are story-wise most likely to be on brains rather than tubes/paste (Blaine, Don E., hell anyone in that circle) never show similar behavioral changes. At first, the changes were moderate, noticeable, quirky...but over the course of the show, something she should have gotten better at has become demonstrably worse.
And I hate it. Having her deeply embody these other characters, often without interpersonal consequences whatsoever, ends up feeling so cheap and shallow. "I'm on X brain" has just become a catchall defense for anything she says or does, with the exception of ruining her relationship with the zombie in the militia whose name I forget. I end up almost wanting to fast forward through the procedural elements to see where they're taking the main plotline, but it's hard to know when or if the two would overlap. Season 4 has some really incisive commentary on poverty, inequality, crime, desperation, and radicalization. So that's been interesting. And the whole "sudden virulent pandemic" thing was bitterly funny, with that season having come out 5 years before COVID - had to laugh at how people lined up for a vaccine, and how there was an almost immediate vaccine. But then, the show didn't have time to explore that resistance, and I don't think anyone predicted how even a legit, obvious threat would become a political issue. Truth is stranger than fiction.
I have no one to talk about this with so I'm dumping a blob of it here.

iZombie also tries to be CSI by incorporating a variety of subcultures and alternate lifestyles, but ends up reducing them to their stereotypes and thus disrespecting them. And I've found that really irritating (and on a couple occasions downright offensive)