Do Roku offer more than Google TV ?

I have never had or seen a Roku device. I have an NVidia Shield TV.

I mainly use headphones or earphones but from time to time I would like to do without them but not only are the speakers of my TV behind the screen but their sound is deplorable.

So I want to add a small soundbar and I came across the Roku Soundbar.

So I have two questions:

1 - is the sound correct (no need for high fidelity multichannel atmos sound, just intelligible sound)?

2 - does the Roku system (as a streaming platform) provide anything more than my NVidia Shield ?

THANKS