I agree the Netflix choices are much better. I've not been impressed with the Amazon offerings that are free with Prime---either in TV or books. But if you are going to get Prime for some other reason, there might be some things on it you like.
Also agree that Netflix has more offerings on DVD than on streaming. But the Netflix streaming is better than Amazon streaming, even the full Amazon TV.
You can always get it and drop it. There's no contract.
I also tried the Kindle Unlimited for a month and found there was nothing on it that I cared to read. Much better selection in e-books from the local library.