Honestly... disappointing. It really doesn't bring anything new to the table and everything that happens in the movie feels either irrelevant or obvious. It doesn't show the story from a different perspective and really feels like a cheap nostalgia driven cash grab. There's so many interesting things to be explored given the rich and open-ended plot of the main series and a good example of it is Better Call Saul. El Camino explores none of them and instead tells you what you already knew (or at least strongly suspected).
Don't get me wrong, it's competently executed. The acting is as good as ever and the shots are really beautiful but you'd expect something more than 2 hours of non-thought-provoking eye candy after 6 years.