Neuromancer is my favorite book. Not one of, but the one.

Same.

After watching the trailer I must say that the overall vibe is substantially off.

Possibly. I'm not sure the trailer give us enough to really conclude that. But here's the thing... at least for me: it doesn't matter. I mean, I don't expect an adaptation of Neuromancer to be an exact match for my mental image of Neuromancer. It is, after all, an adaptation. It's going to be different. And - up to some ill-defined point - that's OK.

I just remind myself that if I want Neuromancer the way I see it in my head, I can always just read the novel again. But watching this show, I'll be trying to remind myself that it is its own work and that I shouldn't judge it by what's in my head. Hopefully I can just sit back and enjoy it and not spend too much time thinking "Oooh, that's not what the Chat is supposed to look like" or "He doesn't look like Ratz", etc.

Is there a line "too far" where it might be so different that it makes it hard to impossible for me to enjoy? I suppose. But at the very least I'm not going to make any assumptions off a 1:10 long trailer.

But it is a difficult book to adapt,

Indeed. I'm no screenwriter, so maybe this doesn't mean much, but I can't even really begin to imagine how you would adapt this and really capture all of what makes it so unique. I'm just hoping they did a reasonably credible job.