I haven't cruised with a Plus package but have it for my 14 day NE and 23 day Panama Canal positioning cruises. Reading all the comments has been interesting.
I was on a 30 day So. Amer. cruise without Plus in 2018, judging by my habits that cruise, a no brainer to have it. I do water, specialty coffee, wine with lunch and dinner, maybe a Margarita in the afternoon and being a carb queen, love desserts.
I've never been one for budgets, a casino person, I'm in my 70s and enjoy myself. I have to pay double for my cruises with what they cost, worrying about my on board $ spent, not happening!
I'm on vacation, plus package sounds like a breeze!