The Oliver Harris edition of Junky is the most thorough version of the book. However, it's no great loss if you pick up an earlier version. Most of the added material is for completists or students, only. The excision of a chapter about orgone boxes, though it upset Burroughs, is for the best.

This is Burroughs first novel and I found it underwhelming within the context of his later works and legacy. The last third to quarter of Junky is when the writing really picks up and we get glimpses of future promise. In particular, the parts where he punctuates a straightforward narrative with a cacophony of sounds and visuals is really effective in evoking a sense of disorientation in the reader. It's a germinal form of cut-up and collage. 

I'm not interested in the junkie narrative or experience but I prefer Jim Caroll's "The Basketball Diaries", which I also read recently, over Junky in that regard. As a warning to the more sensitive reader, like Caroll's book, the narrator is highly unlikeable as are most of the characters. From a historical perspective, it's fascinating to read an account of life in the darker corners of the US and find overlaps of certain neighborhoods and places also mentioned in "Basketball Diaries" and John Rechy's "City of Night."

A notable beat work but not the best.