I can't comment on the specific product offering, as I'm not familiar with it, however: yes, in general cellular is more secure than an open WiFi hotspot. While theoretically sniff-able, it takes expertise and equipment most folks don't have, so with WiFi being cheap and easy to sniff they focus on that. The catch is cost - depending on your cell provider there may be additional costs involved - and speed - cell typically isn't as fast as a WiFi hotspot, though it can be. Truth is I travel with a cellular modem and typically use it.