Been running mine for week or so with the rears (free on current offer) to give more developed initial impressions as a non-specialist user rather than reactions straight out of the box. Linked to QN95A TV and playing Sky downloaded UHD material plus sports together with some UHD Youtube test videos, TV Netflix, Prime and Disney+ apps. Running on E-ARC and adaptive sound mostly, and sometimes on surround sound settings. Couldn't tell any difference. I have compared a few items running the Sky UHD Atmos material versus Blu ray disc e.g. Saving Private Ryan beach invasion which I find is a good workout.
Q Symphony to me is poor when applied. The middle and higher sounds lose depth and to my ear sound a bit tinny when active. Better quality just running the Q800A as the sole sound output - also got rid of regular handshake issues between the soundbar and tv that had it reverting back solely to the TV speakers at intervals or not always handshaking on start up. This is with certified HDMI 2.1 cable. The TV sound on its own is actually quite decent for general viewing.
Q800A is dead easy to set up initially and has lots and lots of power and more than adequate for normal size room, and probably much larger. Not a sign of distortion at higher volumes. To get a more balanced sound in my room I needed to up the volume of the rears a couple of notches and raised both the front and rear heights. I have been thoroughly enjoying the overall rich and robust sound quality so generally very pleased. Very clear sound with nothing muffled even when lots going on. Haven't played around with equalizers other than to up the bass a couple of notches. Musicality sounded good to me linked to iPod. The one issue I have noted is lip sync on sky q live material e.g. news programmes but not on anything else e.g. Sky recordings, blu rays. If I pause the live feed then restart after a few seconds it is pretty much in sync again! I haven't yet tried feeding Sky Q direct to the soundbar HDMI rather through the TV first, and will be giving that a go to see if it makes any difference.
I have run separate 5.1s before but don't have the space now. From memory I am pretty sure that the separates at the front did give a more clearly defined width (duh), though the rear effects unsurprisingly are much the same. That said, some material was giving me a very wide sound stage from the front when I found a sweet spot to sit or stand in. More playing around needed, but so far I like what I hear.