Latency

If I were doing this, I would start with this:

• Download hrping to the gaming laptop and extract (unzip) the files into someplace where you can open a command prompt.
  hrping is a "DOS program" run from a command prompt (C:).
  For example, I have a folder on the C: drive so I can open a Command Window and do a "cd c:\folder".
• Unplug the modem and connect the laptop directly to the modem.
• Verify that the laptop "works" on the internet.  It should get the same IP address as the public IP address that the Orbi system had.
  Test by opening a web browser.  Should work like normal.
  Do a Speed Test (i.e. http://speedtest.net  or http://fast.com)  All is good, correct?
• Open a command prompt as an administrator, change to the directory where the hrping program is and type in:
  hrping -n 10 8.8.8.8
  This will ping the Google DNS server 10 times.  The speed that it reports is the best you will ever get.
  (You could ping 100 times and see if there is any substantial change.)
• At this point, if there is substantial latency, you are SCREWED.

Now that the raw internet speed and latency are established, unplug the laptop and plug the Orbi back in.

You can do the same test, from the gaming laptop when it is connected to the Orbi (ethernet, WiFi, or both).
Try to ping Google, the desktop, the X-Box, whatever else you have that will respond to ping.
I would do at least 500 pings (maybe 100 for Google).  (The 5,000 pings I did in my test took so long I would go have a shower or eat breakfast while they finished.)

If anything that goes through the Orbi, to anywhere shows high latency this is not good.  In my case, only the one old laptop was slow.

This may not be the sort of thing you want to spend time on or enjoy.