Circle 1st Gen vs Circle on Netgear vs Circle Home Plus

From my experience, you would be unlikely to see improvements in your wifi by adding a Circle device. It acts as a "traffic cop" for your network, so all the data going through your router generally will have to go through Circle as well. In my case, Circle caused a very measurable decrease in my internet speeds.

I am surprised your Nighthawk router did not improve wifi over the ATT router. Did you make any changes to the ATT router at all or just plug in the Nighthawk? If you just plugged in the Nighthawk, are you seeing 2 separate wifi networks? If so this might be why you didn't see performance go up. You might want to consider contacting ATT and asking them to walk you through setting up "IP Passthrough" - you could try to read this link as well but it does get technical.

If it were me, I'd try this:

1) Configure the ATT router to be a passthrough device and turn off any of its onboard wifi

2) Connect the Nighthawk to the ATT router, bring up your wifi network, then do a speed test from a kid's wireless device (I personally like fast.com for the speed test)

3) Connect Circle to the Nighthawk and setup a kid's profile. Add the device from step 2 to the kid's profile, then repeat speed test.

If you don't see much difference between 2 and 3 then finish setting up Circle profiles. If the speed difference is a problem, you may want to return the Circle device. In my experience it never got any better, only worse. What has worked for me - mostly - is using Microsoft Family. It isn't as feature rich as Circle, but it is FREE, works across every Windows computer in my house, and I've seen no issues with speed. I only wish it worked on cell phones too!