this is my second time reading this story and my opinion is kinda split. while I can understand it being considered a well written book, I cannot ignore the racism in it. 
the descriptions in the story really are what's appealing about it to me and the only reasons I've reread it (read it once in uni). the descriptive parts about nature are interrupted by the racism of the times, often dehumanising black people (e.g. reducing them to body parts). I understand that Conrad was condemning colonialism (also based on his own experiences with is) but the racist parts should not be entirely ignored simply because of it. 

the essays printed in this version of the book really add to the reading experience and offer some deeper perspectives into the story. Especially Chinua Achebe's essay points out that the racial aspects of the story have been ignored for a long time, so I recommend giving it a read.