You might like Scott Alexander's Unsong, freely available online. On the grounds of Yudkowsky's HPMOR, you could be excused for expecting fiction by rationalist

You might like Scott Alexander's Unsong, freely available online. On the grounds of Yudkowsky's HPMOR, you could be excused for expecting fiction by rationalists to be generally terrible, and it is; Unsong is the exception, and proves if nothing else that Alexander missed his calling.