This is a good writeup of a particular accelerator experience. However, I think the value you get will depend on a number of factors, including which accelerator you attend, what stage your company is in, and what goals you hope to accomplish. For example, I attended Founder Institute a number of years ago, and it was a mixed bag in terms of value, but really provided motivation and a push to produce something that we would not otherwise have had. But that experience and the one in this post are different than what you would get at Ycom, or Tech Stars. Know what you're getting into and what you hope to get out of it, and you'll have a better experience.
The problem is knowing what you are getting into. With big accelerators, like YC, there are tons of resources online and you can get an idea quite easily. For other, it is much harder. Although their websites generally have some information, it's the founders stories that provide the most value. Somehow, it seems that there is more accelerators than content written by founders about their experiences.