I am confused and need advice. We have xFinity wiFi using their modem/router. If I am in the room with it, I get over 200 mbps. However, in my office I only get about 8 mbps. I want to do something to improve the speed there. Moving the router is not an option. Which device would work best for my situation - an extender like a TP-Link AC750 WiFi Extender or a mesh system like the Amazon Eero? Why is one better than the other. Thanks!