Brian wants to know if he should get a mobile phone or a dedicated GPS. Leo says that the benefit of using a smartphone is that he'll get a map with his GPS bearing. He can also cache the maps locally onto the phone and not use data when he's out of reach of WiFi.
The chatroom says a dedicated handheld GPS is more accurate for geocaching. That may be, but he'll get more information with the mobile device. Can he use a tablet? Leo says he could, but they may not have GPS built in. He'd want an LTE data radio built in on a tablet. A mobile device with a large screen is probably better.