@Mastajacobius: As Q-Symphony creates a surround sound experience using your soundbar and TV speakers, the addition of rear speakers may conflict with the feature. If you did decide to purchase the SWA-9500S rear speakers, then I would advise disabling Q-Symphony, as the speakers will provide true surround sound.
I'm interested to hear your thoughts on Q-Symphony with your current set up, though. How are you finding it so far?
@AndrewL thanks for the reply.
I'd like to disclaim that I am no audiophile by any measure and I don't understand all the nooks and crannies of both audio software and hardware so some of my comments and terminologies might be off so forgive my ignorance 
When it comes to Q-symphony I'd have to divide my comment for non-surround content (sports, news, Youtube, live steams) and for surround content (movies, TV shows, games).
When it comes to both non-surround and surround content I can say that with feature on - sound is so much richer, fuller... for the lack of better word. It's almost night and day difference compared to only soundbar audio output where it feels kind of... lacking? At least in comparison. I fell in love with Q-symphony.
Maybe I'd love soundbar as only audio output if I never heard Q-symphony in the first place... haha
However, when it comes to surround content - 3D audio feel / spaciousness of soundstage, it can never really replicate true surround setup with rear speakers which is obvious... but "richer" audio quality still applies as explained above. Exactly for this reason I want to get SWA-9500S rear speakers to just add more surround feel to already amazing sounding setup without losing audio quality that Q-symphony offers... I'll elaborate on this in next paragraph.
In case I would have to turn off Q-symphony, I feel like I'd have to sacrifice that richness and quality of sound for better 3D audio feel. This problem would be especially pronounced with non-surround content as I'd be left with only soundbar outputting audio... without utilizing TV's speakers and rear speakers. I may be wrong here and I'd be happy to hear otherwise...
What prompted my inital post and my worries about losing Q-symphony are Samsung's Brand Ambassador replies on user reviews for SWA-9500S at (https://www.samsung.com/us/televisions-home-theater/home-theater/subwoofers-and-speaker-kits/swa-950...) and I'll quote important bit:
"By design, the surround speakers are supposed to simulate sounds happening behind the viewer. Therefore, most of the time the surround channels are only used for ambient sounds, which are naturally lower in volume."
This enforces my worries explained above. I am debating if my setup is worth the upgrade with SWA-9500S if I have to sacrifice a great feature and sound quality to have rear speakers work.
At least I'd like to have realistic expectations as it's really hard to make decisions about sound by reading about them... without actually hearing the thing work 
To go back to your answer, you say: "...the addition of rear speakers may conflict with the feature."
This may leaves me on square one, in uncertainty. I really don't want to sound ungrateful but I felt this should be a yes or no answer. But fair enough if you just don't know for sure - I'll have to wait for other replies.
Looking forward to hear from other people's experiences!
