Pat is saying she's tired of contracts and the high monthly rates, so she switched to Straight Talk by Walmart. Leo says that MNVOs like Straight Talk are basically a 'rented line' from carriers like Verizon. They do funny things like throttling, charging for overages, etc.
Unlimited with Straight Talk isn't really unlimited, but if that doesn't cause any problems for the user then it's a good deal. They don't have the latest phones either. So sometimes Pat may get end up with last year's model of smartphone. There's really no need to keep up with the absolute latest though. If Pat likes it and the price is right, then it's a good choice.