re: Can someone explain to me how to add a better router to the default combo ATT gigapower

Wi-Fi by current definition cuts your speeds in half. It uses radios to communicate back and forth in half duplex mode (meaning it can transmit or recieve, but not both at the same time). Wired Cat 5 and 6 can operate in full duplex (talk and recive at the same time). I've read that they are devolping radio antennas for Wi-Fi that can do full duplex, but who knows how long that will take to come to market. To add an access point means cutting your speeds in half again.