My experience is excellent after much trial and error. I had the standard FMC boxes with the fiber in-between in my system. Depending on your system setup it can be excellent or a bit sterile. It’s really that system dependent.
Based on changes made, it didn’t go so well one time. Then with other changes it was much better. You really don’t know until you try. For under $100 though, it’s certainly worth a try.
What I discovered far superior was using Cisco boxes. First I tried the Cisco Catalyst 2960. I used two of them with fiber. It was very good. The Catalyst easily bested the generic FMCs. Then I read the Cisco Meraki was better. So, I got a used pair and tried those replacing the Catalyst.
That’s even better. I removed the Merakis’ internal power supplies which took all of five minutes. Looking to convert the second closer to the streamer to an LPS connection as I heard there’s significant benefits there.
Others have gone with even additional modifications to the Meraki with good results. Regardless, you can try it out for a fraction of most of these other audio network switch options. According to Alpha Audio in Holland, the Meraki tested high on its group test. They only used ethernet though not a combination of two with fiber in between I believe. So the Meraki tested great in that application too.
Using the Blue Jean ethernet cables in my fiber router setup. Out from the router to the Cisco Meraki. Then the second Meraki also uses a very short version into the streamer. Running generic Finisar branded transceivers in the Meraki. Transceivers have impact in any application as I've learned. Results are excellent.