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

@lalitk 

"I have taken a single feed from my Comcast modem to my switch which then feeds my three connected devices (DAC, Streamer and Content Server)." 

That is exactly what works for me.  The server is connected to the switch as are two separate Roon endpoints and it all works flawlessly. 

"The 22AWG version is pretty stiff so no sharp bends. The 26AWG version is more flexible."

I too took your advice about the LinkUp Cat 8 cable and use the stiffer 22AWG for runs of 1M or over (the shortest length they sell is 1M), while using very short runs of the more flexible 26AWG to connect switches to peripherals like FMCs.  Regardless of which of the two gauges, those seem to be very well-made CAT cables and particularly the connectors, which appear to be very similar to the well-regarded Telegartner connectors.

Right on @mitch2

I have a Netgear C7000v2 used with Spectrum as the internet carrier.  I've had no issues with it and it covers my modest 1000 sq-ft cottage with WiFi quite well.  What I did notice though is that until I added an Uptone-Audio EtherREGEN device which regenerates the Ethernet signal to my music-server, I was unable to get streaming music to sound as good as that from the same music loaded into my music-server.  So, cleaning up the Ethernet signal is an important part of better listening in my opinion.  

1. Go with direct 1G Ethernet copper cabling wherever possible. It is infinitely more reliable, economical and has much higher bandwidth. 
 

2. Do not “power line Ethernet” products. They do not work. 
 

3. Buy off-lease enterprise grade Cisco switches, firewall and mesh wireless access points instead of TP-Link/assus/Trendnet or any other consumer brand. It will work better for much longer. 
 

4. Use major name jacks and patch cables from Leviton or Belden or Hubbel and use brand-name Cat5E or Cat6 cable instead of cheap no-name low quality cable. 

After reading this thread, I checked my actual internet speed compared to what I am paying for and found it to be only about half what it was supposed to be.  The Comcast/Xfinity website was helpful by showing that my modem is outdated, the non-Xfinity modem options that are considered current, and a link to the speed test.   I then purchased a new DOCSIS 3.1 Gigabit cable modem from the list that will hopefully provide the speed I am paying for.