Cable vs fiber for audio quality

If you are just asking if there would be an audible difference between fiber and cable to the house, I think the answer is no.

Once they provide fiber to the house into the ONT, will you be using the same RG6 within the house you had before, or will it be a new ethernet cable(s)? or fiber to the modem/router?

The difference in sound will be achieved by the last connection(s) before the streamer, or some have noticed differences by isolating the hifi with a fiber connection into their renderer.

You have the deets on what factors a change in cable platforms may provide for you:

- speed

- reliability

I just changed over to fibre optic service provider  for these reasons ( mostly the latter)

As far as impact on my audio performance goes, there is nil / zippo,/ nada differences in my audio streaming performance in a $50K system,

Fiber has lower latency and jitter with all things being equal. But I doubt you'll be able to detect much of a difference in jitter (who knows what the ISP does to the signal before it hits the fiber network leg). Latency is much more likely to be better. I know it made a big difference in my situation. Even things like Netflix loaded much quicker (I had 1G copper and switched to 1G fiber). And it led me to eventually switching my LAN from copper to single mode fiber. I stream a crap ton of stuff off my media NAS as well my music NAS - both located in my LAN. With copper, it took several seconds to que up a 4K movie. With fiber, it's less than half and probably closer to 1/4 the time. I had a 50' run of copper from router to media area. That makes a difference as well.  

All this is now good to know. My main concern was it would be bright, I can’t do screaming at me bright.

I placed my order to be installed Monday. I know to some this maybe an odd question but will this new modem/router need break in. I owned my modem/router before I started streaming, so never new. 

I wouldn't worry about it. Besides, it's going to be on and in use 24/7 from the moment it is installed, so any theoretical burn-in benefits will take care of themselves pretty quickly.