I purchased my x60 3 piece kit from Costco a few weeks back, and while it has improved my network, I'm annoyed that I'm not seeing full wireless speeds on my wifi clients, instead only getting about 60% of the speed my wired clients see. 

I'm running in access point mode with wired gigabit backhaul, and both of the satellite units show ethernet connection to the main deco.

My wired speeds are 325 down / 12 up.  I get this from my main r7000 router consistently while wired.  I get this from the deco app consistently when running a speed test, which means the deco is getting the full speed, and I get this running a wired test consistently from the main deco on a device through its extra ethernet port, so the full bandwidth is at the main deco and isn't an issue with the deco to router segment.

I have tried rebooting, I have tried unplugging the other satellites, I have tried several wifi devices, have tried changing from WPA2 to WPA3.  I have tried going back to router mode.  I have tried enabling and disabling the 2.4 band.  I am always using the same speedtest.net server to minimize inconsistency.  Some folks have mentioned that they changed QOS settings to 1024 down and 1024 up as in their case that was a limiting factor, and I don't have that option when in router mode or access point mode, so that's not a troubleshooting step I can take.

Now, 60% isn't bad, I am glad I'm getting ~195 down, but I should be getting the full amount when I'm less than 3 feet from the main unit, and my other network devices aren't being used, I don't have any phantom machine taking up the rest, etc.

What else can I try?  I would prefer not to return this back to Costco.