I love Google Music. I don’t love the Google Music Uploader. Unfortunately, it’s not smart enough to reliably ecognise when a song in your library is already in the cloud, so if you ever have to reinstall the Music Uploader, you’ll start to notice hundreds or even thousands of duplicate songs counting against your limit and cluttering up your library. Until some Google engineer decides to fix it on their end, you’re stuck with a messy library and a degraded user experience.
That is, unless you are a bad enough dude (or dudette) to follow this guide and leverage Python and the unofficial gmusicapi.