I actually have not dealt with too many customers with gigabit speeds, but a customer finally cropped up with gigabit service through Xfinity.

He was using a Google WiFi system with it. The mesh speeds were only around 100mbps, and even lower when connected to the mesh. I was not necesarilly surprised as it seems like the Google systems cuts speed a lot.

As an experiment I isolated the entire network down to one Google node and the Comcast gateway which was in bridge mode. Right next to the router with an iPhone X I was seeing around 300 or so with spikes as high as 550 very infrequently. I was using Speedtest.net There was very little other WiFi activity around this house.

This got me wondering: with WiFi networks that have 2-3 AP’s and gigabit service, what kind of speeds are you typically seeing to newer mobile devices?

And if there is an old wireless device attached, will it really drag the speed if the entire WiFi down?

This is slightly off topic to your questions, but related in a way.  Has anyone else noticed inaccurate results with the newly updated speedtest.net app/site?  In my house, I consistently tested right around 115 Mb/s down before the app update.  As soon as it was updated, I was getting consistent results around 170 Mb/down.  I doubt that Charter updated our speed simultaneous to the speedtest update, so I am guessing they are bloating their speed results for some reason.

Yes. It can. AP radios always use what is needed for the slowest device on the network.

As far as speeds go, I have a customer on Uverse gigabit, with 2 Unifi AP-AC-LR's and one AP-AC-Pro and I have consistently got around 800 down using DSL Reports speed test. Hardwired was spiking to around 1000 down.

I get between 770 and 790 consistently with a high of 805 in my home. This is Xfinity and EERO Pro with 4 access points, all wireless. My customers get the same results with Xfinity, much slower with CenturyLink fiber gigabit service.

Isn't speedtest.net (OOKLA) now an Amazon owned app?

I've had two projects with gig service...

A google fiber project with unifi hardware and 5 AC Pros which was pulling 350-450 depending on where you were in the house. I'm in the middle of upgrading the second project to Xfinity gig and unifi, currently I have 4x AC Pros and it was pulling similar speeds depending on proximity to the AP.

I use wispy to get signal levels right and tune the channel spacing paying close attention to the 5ghz band for fastest access. Distance matters as the closer in to the AP the better the throughput and as someone already mentioned the AP will slow down to talk to the oldest/slowest device on the AP.

X1 client has asked about MU-MIMO and wants to try the new unifi HD APs. I'm deploying these later this week so will see if that helps throughput.

Do you remember what router you're using?

I actually had a USG router and an AP-AC-Lite on my van so I connected them directly to the Xfinity gateway. I was only to hit about 180 mbps. Not really sure what that was about. I use Ubiquiti now and then and it's been rock solid, although I must admit I don't know all the tweaks very well to maximize it's performance....