What are some alternatives?
When comparing Sonarr and Radarr, you can also consider the following products
Sick Beard - Sick Beard is a PVR for newsgroup users (with limited torrent support).
FlexGet - FlexGet is a multipurpose automation tool for all of your media
CouchPotato - Presently you can watch films and TV demonstrates in a flash by utilizing Couch Potato.
Jackett - API Support for your favorite torrent trackers.
Ombi - Ombi is a front end user facing request system.
Novaroma - Auto Download Tv Shows, Movies and Subtitles.