Hi Oceans. Although I’ve not heard the Sony I do own the Fearless S8F and loooove it. I also own many low/mid tier iems with my long time favorite being the Ikko OH10. I listen to many genres of music including some hip-hop, old school hard rock, acoustic/vocal, classical, lots of jazzy pop, etc. I wanted an upgrade and the S8F has not disappointed. Great fit and cable out of the box.
I did have to spend time finding tips that offered a good seal (Dekoni Bulletz) and when I did the bass really blossomed. I also bought a new balanced silver cable because I run all my iems balanced through a Fiio portable amp. Not really necessary with the S8F; the stock cable is fine (heavy, stout, and nice looking).
Regarding sound Mon nailed it so nothing really to add there. I just love these iems; the detail is amazing!