Wow. I can't believe that someone at Axiom said that.
As someone who spent the time and money to have 4 QS8 surrounds and 4 M3 onwalls for surrounds while having 4 M3 onwalls on my ceiling, and able to switch between the QS8s and M3s for surround duty in an Atmos setup within a few minutes (plan was to return the surround M3s within 30 days if need be), the difference was clearly noticeable.
The monopole speaker design is what "immersive" sound formats like Atmos and DTS:X were designed around, not di/bi-pole and certainly not quad-pole with their more "old school" or "traditional" 5.1 or 7.1 uses where they do great.
One way to think of it, as explained by Dolby themselves a CEDIA back in 2014 I believe, is that the speakers should be treated like lasers. In order to get laser accurate sound placement within a room, you need very precise control over the direction and amplitude of the sound coming from each source. Monopole speakers give the most directional sound out of the speaker designs and using that direction, in combination with the direction and amplitude of the other speakers in the room, allow sound formats like Atmos and DTS:X to be able to very accurately put the sound where it was intended to be.
Using anything di/bi-pole takes away from that accuracy, and using the massively diffused quad-pole setup of the QS speakers (which is a HUGE selling point for regular 5.1 or 7.1 setups, although I argue that the best 7.1 setup in my room was side QS8s and rear M3s) really is not wanted for Atmos/DTS:X.
Can it "work"? Sure. The ceiling speakers will add a level of elevation to your sound stage, but since you want a good amount of separation between the overhead speakers and the base layer (front LCR and surrounds), spraying sound up at the ceiling is counter productive, as is spraying it along walls or at the floor.
The QS10s would sorta be better in that you at least have a woofer pointing straight into the room like Atmos/DTS:X wants, but you are still having audio spilling out all over the place as well. Again, great for 5.1 and 7.1, just "meh" for Atmos.
So take it from someone who actually tried it with a ton of Axiom speakers in my theater room to do the EXACT test of what you are wondering about. Monopole surrounds will yield the best accuracy and "awesomeness" of Atmos/DTS:X soundtracks. Yes, it is a difference you can actually hear if you are able to test like I did, yes it was worth the cost, to me, to test it out. I am just sharing actual results that I experienced and not speculation.
Side note. What do you do when not playing an Atmos or DTS:X soundtrack? Upmix it to Dolby Surround or DTS Neural:X! I don't listen to straight 5.1 or 7.1 movies as the upmixing into these other formats is THAT GOOD.
