So far, not so good. I bought a round-trip ticket for a non-stop flight from SLC to DC on Frontier Airlines, and paid the extra fee for a carry-on bag. When I downloaded the Frontier app and checked my reservation, it states that the flights in fact do have stop-overs in Denver, and there is nothing about my carry-on bag already being paid for. In fact, the app is asking if I want to pay to bring one. So, how do I trust a reservations website that either doesn't know or is flat out lying (not sure which is worse) that the flight is non-stop when in fact it does have a stop, and takes my money for a bag reservation that didn't get made?