Well, technically the QS series are quad polar.
Per the main QS product page, "... multi-directional Quadpolar Surrounds ..."
As for Atmos of improving a 5.1 or 7.1 setup, I will say this. I continue to hear this at CEDIA every year... "Atmos won't make a poor 5.1, 7.1, or 9.1 setup sound better. You need to have a solid quality foundation before thinking about adding height speakers."
Now you can hit a point of diminishing returns, or a low ROI based off of your own wants... Is your current setup providing plenty of clean power, or would "going separates" or upgrading speakers be worth the cost? vs Is your current setup providing a solid enough base that jumping to Atmos would be a great upgrade, or do you again need to tidy up a few sound issues with your setup (including room acoustical treatments)? Those are rhetorical questions not specific to you, but just things that people should weigh.
For me, I wanted to jump into Atmos back in 2014 when I was at the Dolby booth at CEDIA when they made the announcement. I already had a lot of room treatments, and built the room with good mathematical dimensions, had added a 2nd sub to smooth out bass, etc, so I had a very solid base to work with making the jump to Atmos the right decision for me. I opted for a significant upgrade to my $800 Onkyo receiver with my Anthem MRX-1120 which really made my Axioms come to life.
It certainly wasn't a cheap upgrade either. Traded in four QS8s, bought eight on-wall M3s, and bought the Anthem (which is still a current model), so you can do the math and it was a pricey upgrade for sure, but it was the "right" decision for where I was at.
