Don't know about the Princess Grand, but I was on the Golden Princess last year and the coffee was awful. At least compared to the coffee back at home (Puerto Rico). We are big coffee drinkers and make (in my opinion) great coffee.
Been on three and they are all about the same. I don't recall seeing a title "coffee brewmaster" aboard any of my ships. Have you seen the kids make "specialty coffee" at the new McDonald's McCafes? They have a recipe book complete with pictures which they follow (and I might add not too well at times). On a recent HA ship we paid for two cups of latte and you would not believe the difference. They were susposed to be identical.