@ghostchaser relatable! Too many were introduced too soon to develop appreciation for their personality... And then some, I think.
I have done an interesting trick: I've re-read the book right after I read it the first time, skipping the more action-y parts.
For me it's very interesting to think about radicalism and to investigate Conrad's actions during the expedition.
The writing was indeed absolutely stellar, to think that it was Zelazny's debut. I'm finishing the book right now, and I hope it'll be a 4½ because the ending is a bit muffled.