Being somewhat picky about sound quality, I dumped Sirius long ago. The quality just is not as good as so many other options out there today. I've tried APPLE RADIO, which is better quality than Sirius, but still lacking.
Pandora quality is much better, but I've resisted signing up for the subscription service to dump the ads. I've settled on Amazon Prime Music, since I have a Prime subscription through work. Sound quality is as good as it gets and the selection is terrific. Not to mention that the Amazon Music app is now also CarPlay compatible.