We decided yesterday to grab the drinks package. I'm not sure we will break even but the things that swayed us were these

Convenience of being able to get both alcoholic AND non-alcoholic beverages anywhere
No need to sign for anything - not sure whether this would happen as it looks like cards are used?
15% gratuity added to drinks which are paid for
5% extra discount on drinks package takes it down to $68.4/day instead of $72
Can try things out to see if we like them. I read that you could try a cocktail you hadn't previously tried and if it wasn't to your taste just grab a different one. This seems significant as it will give us a much better experience/choice

Out of all these the convenience factor was probably the biggest one.
I'm not sure whether we will get any kind of record of what we "spent" with the drinks package afterwards? Do you get some kind of printout?

In any case I'll let you know how it went in a few weeks time