I've seen it before and absolutely hated every second of it.
In general, I found surreal avant-garde movies entirely reliant on heavy symbolism boring. I don't mind symbolism as a rule but when every character is an anthropomorphized something and the plot only makes sense if you unravel each symbol, it's tiring and eye roll inducing. So, it had an uphill battle regardless of what the movie was about.
But I also found the content awful. It's bloody and gross. Again, I don't mind as a rule, but I'd like it to have a point. In El Topo, it all feels shocking to be shocking which I find very boring.
And there's a for real, planned rape in the movie. So, fuck El Topo and Alejandro Jodorowsky.