I've never read Unsong, though I mean to. Scott Alexander is the SSC blog guy yes? His blog is good. I was about to say I enjoyed his other fiction like The Metropolitan Man (superman ratfic) but after googling it I see that it's actually a different Alexander...
You may or may not enjoy HPMOR...
I mean, I think it doesn't matter if he's a good philosopher or not since that doesn't really affect your experience of this story. To me, it's clear that a lot of the hate for him as an author (not philosopher) is very mis-informed and sophomoric. It has the smell of people hopping on a...