I let my initial subscription expire on a new vehicle, then never re-up it. Have done that for years. The only pain involved is continually having to answer the phone calls from them after that.
We have close to a terabyte of MP3's available to us, and have whittled that down to about 50GB of riding tunes for the bike, and then around 62GB for the Audi. I have the same 62GB of the music we like the best on my S7 phone running Poweramp, so I can bluetooth that music anywhere.
I can't see spending $100+ per year on a vehicle just for music. I know, I know...to each his own.
On the other hand, if I was buying Sirius or XM for 3 vehicles each year, in ten years, I've spent $3,000. On music. That I never owned, and won't be able to pull up again when I want to hear it. $3,000 will buy around 500+ CD's from Half.com. That's a heckuva lotta music, my friends.