It's probably my favorite sci fi book. First Heinlein I ever read and it's the reason that I later read almost everything he's written.
It has some great savvy political takes. The loonies were more free when they were ruled by an absolute monarch prison warden then they were under self-governance. All the leaders of the revolution were freedom loving, but the end result was less freedom than before. The loonies really didn't know how good they had it under the warden. This is a deliberate parallel and comment on the American revolution.
The only thing I think was a slight mistake in the book is how Manny comments a few times how it was a mistake for the warden to centralize everything around Mike, while the revolutionaries also put themselves at the mercy of Mike. I thought it would come back to bite them at some point but it never did.
All in all great book, must read for any sci fi fan. Definitely recommend it to your friends if you want to liberty pill them.