We do the math before deciding to add; the math works for us on this cruise. Usually the internet is where it loses value, but I will be working this trip, so I will need internet every day.
We also consider whether we will want to book excursions; we will on this trip, so the $200 credit will be used.
Always eat at Pinnacle Grill, so that will all get used, too.
That leaves $208 for beverages. Being coffee and juice drinkers then adding water for excursions, not much will be left for the occasional glass of wine or "other" drink. We'll drink 1 or 2 "other" drinks each day, so we will use it all.
I have called 6 times, but have not been able to reach someone who can or will add it. I'm told it's not combinable w/my cruise.
So, I continue to try via app & web just in case.