Be advised that 750Mb is a combined Wireless connection rate between the wireless on the router and the wireless connected devices. Its not a actual data transfer speed. Its 300Mb on 2.4ghz + 450Mb on 5ghz for those devices that support 450Mb CONNECTION RATE on 5Ghz =750Mb. Wired LAN cable is 1000Mb on the LAN ports.
You can check the connection rate of wireless connected devices on the routers web page under Status/Wireless
What wireless modes do you have set up for 5Ghz?
Recommended in single mode N, Auto channel width, WPA2/AES only. Auto Channel Scan. Any HT20/40 co-existance disabled.
I realize that, but 150Mbps still isn't close to 450Mbps. All of these devices support speeds up to that, as I've tested them on a router that allowed that speed.
This is what I'm getting with every device on the 5ghz band:
These are my wireless settings. I don't have any option for co-existance.
My wireless are those, except I don't have an option for co-existence. Also, factory resetting it did not work.