Thanks a lot. I just did a quick test and tried the mixed band suggestion (with no VPN):
Direct WiFi Speed to my ISP Modem with no GL-INET in the mix - 287mbps/16mbps (dl/upload)
Test 1: PC - 5Ghz GL-INET Wifi - ISP Wifi 5Ghz - 87mbps/15mbps (dl/upload)
Test 2: PC - 2.4Ghz GL-INET Wifi - ISP Wifi 5Ghz - 63mbps/15mbps (dl/upload)
So it still looks like the same band use is a bit faster.