DH and I are starting to seriously discuss a Galapagos adventure.  We’ve done some research and I have a few questions:   1. how does one pick a ship?  There seem to be pros/cons to all 3.     2. what is the flight credit stuff I read about?  I’m trying to understand the pricing.  The price I see if I start to book, does that include this flight credit of $500/person if I book flights through celebrity? Doing a pretend flight search on Google flights, there are flights under tha