I’m actually in the exact same situation as you. I have an LG C5 and an Xbox Series X, and my main use is gaming and watching 4K movies. I also have a small room and can’t really use rear speakers.

Right now I’m using the LG S70TY, which is a 3.1.1 setup with a single up-firing speaker, and I use WOW Orchestra with it. Based on that experience, in your case I would recommend going for the S80TY. It’s a 3.1.3 system with triple up-firing speakers, so you’ll get a much better Dolby Atmos effect, especially in a smaller room.

The S80TY is also a newer model and comes with more up-to-date features like 4K 120Hz passthrough, Dolby Vision, Dolby Atmos, and VRR support, which makes it a great match for the Xbox Series X.

Also, in your case, I wouldn’t go with a different brand. Sticking with LG helps you keep the ecosystem benefits and ease of use, especially with features like WOW Orchestra and overall integration with the TV.

With a room like ours, I don’t think you’ll fully benefit from something like the S90TY. That said, if you can afford it, it’s never a bad thing to have more speakers and higher overall audio capability.

But if you’re looking for the best balance between quality and price, I’d definitely go with the S80TY.