I want to replace the router/modem Comcast with a high quality for streaming

Sure. The fundamental improvement it offers when compared to the other routers I auditioned is a very significant reduction in the noise floor. I hear all of the musical benefits one would expect from a darker background: deeper and more realistic bass, more natural expression of note overtones and decay, better presentation of spatial cues and more “natural” location of instruments in the soundscape, and I hear more deeply into music to discover things I’d not heard before.

For reference, my digital path:

router - generic cat-8 - etherregen - DHLabs eth cable - Aurender N200 - Von Gaylord Legend SPDIF & DHlabs USB - Devialet Expert Pro - Reference 3A MM de Capo BE

@mitch2  see my response above

I recently had my ISP install the most recent router they have available for their customers: Calix. I was surprised to see and hear significant improvements in the video and audio performance on my television and the audio delivered from my Aurender streamer. I had no expectation that the router would affect system performance at all, let alone so significantly.
 

For reasons not worth going into here, the Calix does not work for me in my current home. So, having observed that their router made an obvious and easily detectable difference in the delivery of audio and video information, I decided to buy three different routers to determine which offered the best performance for me in my home and with my system: Eero 6 mesh, tp-link axe5400 mesh, and tp-link axe7800 gaming router. All three resolved the technical problem I had with the Calix, but their handling of audio and video differed significantly. Without belaboring the point with too much detail, the two mesh systems’ performance were approximately equal to that of the Calix. But, the TP link gaming router delivered significantly better audio and video services than any of the other three. At the $159 Black Friday price, it was one of the cheapest, yet effective tweaks I’ve made to my system in years. I highly recommend it.