I think that Amazon Channels is worth it. I subscribe to 2 of them , Lifetime Movies for my wife, and the DocClub channel for me. Both are relatively inexpensive - the DocClub channel is $2.99 per month and it has around 350-400 documentaries. There are two aspects that I believe make the Channels a good option. One is that many of them cater to specific interests which may not be met by the major providers, and the other aspect is that they are accessed through Amazon...whether the Amazon page on your web browser, or wherever you may have the Amazon Prime app on your SmartTV, or from the homepage on the FireTV.
I would like to know if another service has the bundle of HBO/Cinemax, like amazon? I do not think the owner or founder needs anymore money. They are raising the prime memberships again. I can not afford this. Plus I have a feeling it is not going to stop there.