I didn't realize my Music sub was getting me a Red sub also. Thought it was just a trial that would nag me when it ran out or something.
I use Google Music mostly for a few specific stations (like 90s alt ballads) and when I fixate on bands so I can go and just play top songs and I'm set for a session of gaming (Volbeat atm, but ranges from Foo Fighters and GnR, to Kanye West). Also use it for one-off songs for my kids (Watch Me and Gangnam Style, gah).
Problems with the quality of results I'd get from Spotify were what eventually soured me on it. I haven't had an MP3 collection for several years.