Reviewers are overwhelmingly negative on Hopper as a booking service. The recurring complaints are failed reservations, bait-and-switch room or flight details, canceled or changed bookings, and long refund fights even when hotels or airlines approved them. Customer support is described as hard to reach, slow, scripted, and sometimes gated behind paid tiers, leaving users bounced between Hopper and travel providers. A small note of praise appears for price prediction and occasional successful bookings, but reviewers say the app becomes unreliable and costly as soon as anything goes wrong.