R7000 much slower in Router Mode than AP Mode

I just upgraded to 500Mbps service.  I'm getting around 450 to 460 Mbps straight off the ISP's modem, and about the same when using the R7000 in AP Mode... however much to my dismay I'm only getting around 70 Mbps, sometimes just over 100 Mbps when running the R7000 in Router Mode.  This is after resetting to factory settings, leaving QoS turned off, and changing no other settings after factory reset.  Any ideas?

Totally confused because in researching this, other people seem to get much higher speeds in Router Mode than I am, and if anything there are comments that AP Mode doesn't enable hardware acceleration from WAN to LAN ports resulting in slower AP Mode speeds (but I'm getting the opposite).