Exceptional stereo vs average 5.1

For some context, I have what would be considered a pretty average 5.1 system in the community. Sonos Playbase, Fives for surrounds and a sub.

I'm getting a stereo setup which I am planning on using near 100% for music; pair of R3 Metas at a minimum. It has be wondering, how would a great stereo setup compare against an actual 5.1 system for movie content.