Depends what you want to do. All of these are recorder/downloaders for streaming services such as Netflix, Prime, Hulu, etc.
If you want something to just integrates with channels. And all you want to do is download the occasional eppisode or series. Then get Playon Cloud. Its $0.10 - $0.15 per 720p recording. Playon Home (desktop based) is also good for this.
If your goal is to data horde large volumes of streaming content for offline consumption in Channel/Plex/Kodi/etc. Then the 720p limit and recording at 1x speed sucks donkey balls.
In that case you could use apps like these. In which case i like Anystream. I have not tested StreamFab but it looks to be equally as popular as anystream.
I chose to download from streaming service because i don't trust bittorrent / usenet / direct download sites. As well as potential for virus. There's also inconsistent encoding methods, bitrates, file name structure etc.
Things like Playon Cloud are legal-ish under law. (Playon is essentially time shifting)
