I haven't read this one yet, am waiting for it to be delivered, but I chuckled at your para about Charlie et al. Yes, I've always found them - well especially Charlie & Simon, & the latter's relationship with Proust - a wee bit unbelievable & tedious. Hard work. Crime novels tend to have dysfunctional anti-hero-type cops, & at least Hannah has been original as concerns the nature of the dysfunction, but these people are so screwed up it's a wonder they function at all. I thought I was a bit neurotic but am a rock of emotional stability compared to Simon (& to a lesser extent Charlie). I know objectively that there are people this emotionally constipated, but I can never quite picture Simon as a coherent character: is it asperger's or is he actually psycopathic, & how for long can this 'love' affair limp along (I'll have further clues when I read the book, I hope). Living with such a person is only possible with a strong dose of denial, or complete emotional detachment (which Charlie definitely doesn't have). And if I remember rightly Hannah doesn't believe people can change (a view I share myself). I find myself wondering if in a future book he might turn out to be the 'perp', though as far as I can remember he isn't physically vicious.
But my real point is not whether such people move among us, but that Hannah's narrative, in spite of or because of the lengthy navel gazing never convinces me as to the authenticity of these characters & their involvement. Sellers & Gibbs (that's their names!) are more two dimensional but more believable.