Glad you like it, its my favorite prosumer router.
If needed the Mesh extender works very well.
Did you try to use Quick Connect for remote router management?
Dont’ fotget to enable the auto update for software 
Putting the Comcast box in bridge mode is ideal. Cox doesn’t allow us to do that 
In case you are renting that stupid Comcast modem/router box. Buy your own modem
I appreciate the recommendation.
Do you favor Safe Access, or Threat Prevention?
[For Safe Browsing, not using (and not interested in) Google Safe Browsing.]
I’d like to add an mr2200ac, but retailers have lost their minds and are price gouging, or are sold out.
Coverage is really good. Unfortunately that lighter area is near where my GF sometimes does video calls.
Sorry for my slow reply, I needed to access a RT2600AC to find out what you were asking about.
Yes I like the Safe Access feature with only the “Thread Intelligence database” enabled. Not feeling comfortable having Google snooping into a network with the “Google Safe Browsing” option.
I always use the Cloudlfare DNS servers in the WAN setup. Since you were planning to install a Pi-Hole I suggest selecting the cloud flare DNS servers.
Another very important security feature is the option to auto-update the firmware.https://www.synology.com/en-us/srm/feature/device_content_control
Thanks @MacExpert!
Yes, I have a pi-hole docker running on my NAS, and am using CloudFlare’s 1.1.1.2 (anti-malware) for DNS.
For those curious about the RT2600AC router. Here is another feature you might be interested in. It allows you to connect a 2nd ISP so it can automatically switch automatically to your backup ISP.
For example, you can connect a USB cellular modem or even your iPhone as a backup ISP for your entire network 
