After about 7 months, here are my comments:
With this system you enjoy music, action movies on the internet, and you hear speeches in videos and radio CLEARLY — even from several meters away.
I am impressed with what I hear, and I bought it mainly for music, but now I even sit down to watch action movies just because it turns the living room into a cinema with amazing sound separation, while the performance of very low, low, mid, and high frequencies is so good that — personally — I have never experienced it in any other home audio system, because there is no distortion even at high volume.
I should note that it was paired with one of the best TVs overall — and especially in terms of sound — the Samsung S95F, and they work together in Q Symphony.
The soundbar and subwoofer connected effortlessly to the TV and automatically entered Q Symphony mode. The soundbar was also added to the SmartThings app — as was the TV — for control from the phone for both devices.
I use it for lounge, pop, Greek popular music (e.g. Economopoulos, Ploutarchos, Terzis, etc.), rave, heavy metal, blues, disco, and trance.
Without a doubt, this audio system produces excellent music quality WITHOUT DISTORTION even at very high volume, despite its relatively small size.
Electronic, techno, trance, pop, disco, lounge, and heavy metal music are pure enjoyment because the subwoofer works a lot too.
With Greek popular music it is just as amazing an experience because the vocals and bouzouki, bass, and drums are all heard very clearly, while you enjoy powerful bass.
In heavy metal (Metallica, Iron Maiden, etc.) the power of the sounds takes over you, while the vocals are crystal clear too (depending on the file, of course).
Blues and jazz are heard at lower volume, but even here the sounds are crystal clear and enjoyable.
In conclusion, for many music genres but mainly for electronic, rave, trance, techno, Greek popular, and pop music, the sound is fantastic because you want to listen mainly at high volume and this soundbar lets you do that easily.
Q Symphony (TV and soundbar playing simultaneously) works flawlessly. I turned on the following functions: SpaceFit Sound Pro, Active Voice Amplifier Pro, Adaptive Sound, Voice Enhancement, and Bass Enhancement. Also, in channel level you adjust from -6 to +6 the Center, Side, and Front Top channels to set the sound volume from each corresponding channel. Very recently, I set them all to +6, and the clarity of the sounds is even higher when the central sound is at a lower volume.
The subwoofer, which is only wireless and does not disconnect at all with fiber 300 Mbps, in my opinion should not be placed next to the TV if you want to enjoy the work it does — and it does it very well. I placed it 4 meters away, 40 cm from a wall corner, and it fills the left side of the room with very low frequencies, blending perfectly with the soundbar and TV on the right side of the wall.
What I understand is that at 'low' volume (up to 25% of the total), the soundbar speakers take almost all the load and the TV sounds very soft. But as you increase the volume — and especially from 30% and above — you can properly hear the TV speakers too (which are excellent), and that is where the party starts. For volume up to 15% of the total, with the windows CLOSED, there is no need to warn the neighbors, although you keep wondering whether someone is being bothered — it is really loud. In summer, at 15% volume, the neighbors will hear it normally.
This applies for volume up to 15%, although even that volume is so high that it is not for listening to music while a family member wants to work/study/relax, etc. That volume is for enjoying music loudly, alone or with company.
On the second day of use, I decided to test what it does at high volume. I informed the building manager by message that I would raise the volume for a 5-minute test. I took it up to 84% with rave music, turning bass and treble almost completely down. At volume from 30% and above — which is only for parties and you BECOME ANNOYING — you feel 17 years old again and one with the music. It really fills the living room/kitchen with sound, the floor shakes, the sofa, the furniture in general, the walls, while the sounds are incredibly clear. Of course, it sounds very loud throughout the whole 100 sq.m. house, but I did not have time to understand whether the other rooms were creaking because I was anxious not to disturb the neighborhood. Wonderful!
I also tested it with dialogues and documentaries, mainly from YouTube news material and an old Greek film. The key is that you need to lower the subwoofer to -12, and then the voices are clear and loud while you have voice enhancement and active voice amplifier on. You hear speeches clearly even when you are in another room at 9 meters. At 10-15%, the voices are heard very loudly and clearly throughout the house.
As for movies, I have watched Jurassic World, Vertical Limit, Gran Turismo, Mile 22, and several others. These, because they have many sound effects, offer a top experience with shakes in the very low frequencies. I set bass to 0, subwoofer to +1/+2 at most, while the sound volume is no more than 11%. You enjoy hearing all the sound effects: screams, dinosaur roars, explosions, engine noises, avalanches, objects crashing to the ground, etc. All sounds are amplified. The dialogues, breaths, whispers, whimpers, sighs, footsteps, groans, shrieks, and other human sounds are all heard very clearly and loudly. Sometimes you wonder where the sounds are coming from, such as birds chirping, water drops, or some bang. You wonder whether you hear them outside on the balcony or somewhere else in the house...
30 stars from me because, at a relatively low cost, you get uninterrupted online access to fantastic sound without distortion, while it performs perfectly in a large home space and you do everything from your phone.

It is worth every one of the 420 euros it cost, and bravo to Samsung for the experience it offers! I wonder how I never thought of buying a soundbar years ago...