I just finished myself. In general I wouldn't say I loved it, but I literally just finished a couple hours ago so it's still settling and unfolding.
One thing though, in response to your spoilered issues. I didn't realize this until halfway through for obvious semi-spoiler reasons, but even though it seems like an omniscient narrator, it's still basically Lotto's perspective. Maybe not his perspective, since there's still things he wouldn't know (the door sex scene for example), but still his ... outlook. If not through his eyes, then through his rose colored glasses. So it's a bit of an unreliable narrator, not just in the details, but also in the tone and impression of Lotto and what he deserves. That's why it comes off as so aggrandizing and, in retrospect, dismissive of the rougher edges of their lives. Like for example his shitty friends, I feel like the tone of dealing with them was "yea they have some problems but they're not so bad" but that's because that's how Lotto feels about them, not (i don't think) how we are necessarily supposed to feel about them.
This becomes more obvious once you hop out of Lotto's perspective. I might have wished I had that understanding of the skewed perspective earlier, but I think that's actually one of the things the book is "about". The intersection of individual perspectives, and how strongly your interpretation of events and your own past is influenced by what you imagine of yourself.