Boost Mobile or AT&T?

My family is looking to switch phone companies... And I have been hearing about the Boost Mobile unlimited everything for $50/month and the rates drop down over time. I feel like AT&T would be more reliable but their monthly plan would cost a lot more for my family in the long run. I just think that there is some kind of hidden catch with Boost Mobile's plan and am very skeptical about it.... Someone clarify this please!! :] Thank you