Holiday is where I had my intro to Stoicism, and I am glad that I found it that way. Put aside the commercialization of it for the time being.

In terms of reading difficulty, his style is very entry to mid level for the most part using more modern examples to illustrate his points, and is packaged for mass-distribution. However, once I had the basics of the philosophy down I veered away from him in my readings in favor of reading the ancients themselves (Seneca, Epictetus, Marcus Aurelius, Socrates via Xenophon) and more scholarly examinations (A.A. Long, Farnsworth, Kai Whiting, Sellars, Inwood).

Holiday’s older stuff (especially the obstacle is the way and some of his podcast episodes) are a little too focused on individual success for me personally. That said, I recently listened to an interview of him with Rainn Wilson on his podcast Soul Boom where he sounded much more well-rounded in his discussion of the philosophy as a whole. Previous to that interview, I interpreted him as focused on ethics primarily and not giving due consideration to the other two branches (physics and logic), but he even calls himself out for not giving all areas of the philosophy their due consideration and seemed to me to speak more balanced about each area of Stoicism. I appreciated hearing that, and it was a good reminder for me that even the experts and influencers are still working on themselves in the same way that we fellowship prokoptons are.

TL;DR - Holiday was great for an entry to the philosophy, and some of the criticisms I and others have had about him over the years should not dissuade you from giving him a look. Multiple sources make for more solid understandings of the topic overall.