After have good luck in years past, last year was different. That's when I almost got really burned. Don't know how it happened. Maybe it was picking seats. Maybe it was early ticketing. I do know, with 100% certainty, that the fare was "Flexible." To straighten things out I had to send a certified letter to the Princess president to plead my case. My letter finally resulted in Princess straightening out the mess. What I thought at the time and still do, is Princess needs to post, in bold print, the financial danger of picking seats as well as the danger of early booking.
Now I'm once again, maybe stupidly, looking at EZAir with United. But there is a big problem. EZAir is more expensive than booking directly with United in both Economy and Economy Plus. In First class, even though EZAir is ever so slightly cheaper than United, the actual flight schedule detail on EZAir is different. The reason is that the United website updated the schedule overnight while EZAir did not..
Repeating to myself "Do not use Princess EZAir."