I've been using it for years now and it's great. Not only for Youtube videos, but also for a lot of other video hosters, up to and including TV stations such as the German ZDF or the French Arte.
To fully use its features you should install ffmpeg though. Youtube-dl will automatically use it if it's in the PATH, and then can download Youtube videos with higher frame rates and resolutions (they store video and audio in separate files, and ffmpeg is used to mux both together). ffmpeg is also required to download from some streaming video hosters.
For me it's essentially:
youtube-dl -F '<url>'
to get the list of available video and audio formats, followed by
To fully use its features you should install ffmpeg though. Youtube-dl will automatically use it if it's in the PATH, and then can download Youtube videos with higher frame rates and resolutions (they store video and audio in separate files, and ffmpeg is used to mux both together). ffmpeg is also required to download from some streaming video hosters.
For me it's essentially:
to get the list of available video and audio formats, followed by and then wait for the download to complete. And to self-update youtube-dl (because it gets updated just about every day).