I discovered Castaneda at the ripe old age of 18-ish...

It also happened to correspond to a time of psychedelic experimentation. Despite the drug piece, I dove deep into those precise aspects you point out dwai, and it was my first step on the spiritual path. As in the books, the psychedelic experiences seemed to serve the purpose of shaking me out of the dream of mundane reality at the time and open my eyes to different ways of seeing.

I reread several of the books about a decade ago and thoroughly enjoyed them for the second time.

I happened to read his book The Art of Dreaming while on vacation many years back in the Dominican Republic. I recall lying on the beach, reading and suddenly having complete certainty that I would dream lucidly that night. Sure enough, I had extended and quite wonderful lucid dreams that night. 

I was disturbed at some of the negative things that seemed to develop around him in the end. Never got into the tensegrity stuff or his last books. His works did lead me eventually to Don Miguel Ruiz which I highly recommend as well. 

I discovered Castaneda a few years after coming to the US.  Nothing in his books was even remotely similar to anything in my cultural upbringing, and everything went against its grain.  I was raised in the traditions of "intelligentsia," a rather unique Russian phenomenon which in English, Wiki describes as "a status class of educated people engaged in the complex mental labours that critique, guide, and lead in shaping the culture and politics of their society."  Which is not wrong but it also proceeds to assert that the members of the "class" are known as "intellectuals" -- and this is, at best, only half (or less) of what an "intelligent" (a noun in Russian that does not equal an "intellectual" and does not mean the same thing as "someone intelligent" albeit includes that too) encompasses.  Part of being that implied having accepted pretty high moral standards for oneself (with or without demanding them of others) -- usually way higher than the average level maintained by the society as a whole.  More honesty, more human decency, more intellectual and emotional courage, more altruism were usually part of what defined that status.  Another part had to do with manners and meant something not unlike what "a real gentleman" or "a real lady" used to mean, but without the aristocratic bloodline connotations -- a member of intelligentsia could come from any social stratum, and if they came from the lower classes, they might be referred to as "a first generation 'intelligent'," whereas a descendant of a family of "intelligents" was  "a hereditary intelligent."  I was that, and it meant many things -- but shamanic, psychedelic, tribal, esoteric-spiritual etc. explorations were not part of the deal.  Quite the opposite was true -- you primarily accepted Eurocentric culture as your birthright and were expected to feel right at home everywhere therein, but you were never encouraged to venture too far from that home.

So, to me, discovering Castaneda -- I started with the very first book, The Teachings of Don Juan -- was a bit of a cultural shock.  And a bunch of pages into that shock I found myself laughing uncontrollably over the scene where Mescalito turns into a magical dog with streams of light and water bursting out of his body instead of fur (if I remember correctly), and Carlos plays with him, only to find, when he comes to his senses, that what others observed was that he was chasing the poor dog (the real resident dog) and urinating on him on the run, scaring the dog shitless.  I was laughing because it was hilariously absurd, but also because something about that scene rang an ancient bell...  My grandmother used to have a potted palm tree in her home, and when I was about two or three, I used to dream, repeatedly, that the leaves on that palm tree became transparent and I could see light and water streaming through them and the whole thing turning into a beautiful fountain -- and that was my signal that I have to wake up and go potty.  When I was done laughing, I gave the book (and the ones I read after that one) my full attention.  

I laughed again -- with delight -- when a couple of years later I came across this irreverent Zen poem:                   

On Mount Wu-tai

clouds are steaming rice;

before the ancient Buddha-Hall

dogs piss at heaven.  

I like the concepts, some of the books.  Don't like the man.  But he opened up the eyes of Western readers to some powerful concepts.  

Are there other authors who expand on his subject of esoteric spiritual warrior, but do it with more authenticity? 

< I see Steve recommending Don Miguel Ruiz>

I devoured them in my late teens - many things struck me, but the visceral nature - being with him in being lost and coming back was exceptional.

You could feel the dryness and hear the desert and wait on the side of a road unknown only to find a hand reaching for you all soiled upon yourself. 

It was an exquisite motivation for practice and a friendly companion in the intensity of great change and completely new environs - both inside and out. 

It was also having a teacher and birds and dogs and beings everywhere and nowhere - excitingly unpredictable but with developing practice and a whole way of living - not inconsistent with my current practices at that time. It was practice shared with no deodorant - alone, silent but for the incredible.