I saw this at the cinema and had to get the DVD as well. The climbing sequences are great, suspenseful and well filmed but it's also the exploration of Alex, his background, relationships and attitude to life that make this compelling viewing. The free solo of El Cap ascent makes up the last 20 minutes or so of the movie but is still so suspenseful even after many viewings.
This is a most interesting story which is doubly of interest because it is real. I found myself squirming in my seat at some of the situations encountered. Dramatic confrontations with the possibility of death.