I thought I had reviewed this earlier, and now I've forgotten the specifics of my thoughts, but the brunt of it is: I enjoyed the first essay "Existentialism and Human", but after that when he got into his philosophy of being and nothingness I got tired of it pretty quick, read half of it and skipped through it after that.
There's a type of discussion where the verbiage is so abstract that instead of being grounded in anything, it only stands on other abstractions, all the way down. This can allow people to easily have contradictory intuitions about a subject and the only way to get on the same page is to endlessly define terms and for any outsider to make any sense of it they have to adopt the entire edifice of ideology. Theology wholly falls into this category, and any ideology does to some extend, but it's nice when there is a better ratio between the number of things we can check in reality and the number of words said about such things.