Because they're owned by Telus, Public Mobile uses the Telus Mobility network. That's a really good thing, because year after year Telus takes the prize for the fastest, largest, and most reliable cell phone network across Canada. They have coverage for 99% of Canadians, and you get full access to that when you're a Public Mobile customer.
Public Mobile plans put twice as much mobile data in your pocket for half the price of most plans with premium carriers like Telus, Rogers or Bell. While they compete directly with Chatr and Lucky Mobile, Public Mobile is the only one that lets you switch to full-speed LTE data. It costs more for a lower data cap, but it's nice to have the option without having to switch carriers.