This was our first time on Princess, as we had typically sailed on Carnival in years past. I will say that Carnival cruises can be a lot of fun, but we were going for a relaxing and enjoyable vacation, ideally free from kids and rowdy groups. Princess delivered.
The Ship
The Grand Princess is an older ship, but she wears it well. The interiors have been updated probably several times since its construction and I found the decor to be neutral with a side of elegance. It isn't hard to find examples of the ships age all in all, but it wasn't necessarily detracting from the experience. If you want to find something to complain about then I'm sure you can, but if you want to enjoy a laid back vacation on a well laid out and apportioned ship, then I'd recommend the Grand. The amount of public spaces, 4 pools and 8 hot tubs ensured that no area was every overly crowded. The majority of the time, when we wanted to go for a swim or a dip in the hot tub we were by ourselves. Our itinerary involved a lot of sea days, so having a ship that didn't feel crowded made the sea days all the more enjoyable. We were always able to find open seats / loungers in the areas we wanted to be in and usually had a fair amount of privacy at that. The aft portion of the ship has (essentially) 4 decks available: The pool and loungers on 12, the Lido Deck / Horizon Court patio with tables and chairs on 14, the covered lounges on either side of Deck 15, and the hot tubs on deck 16. The amount of available space in this area was awesome and really made the trip for me.
Typical interior cabin. No complaints there. The location was great. End of the hall, next to some of the high end suites. I can count on one hand the number of times we heard noise in the room that wasn't coming from us. Close proximity to the pool and Lido deck above. Bit of a walk from the lower level activities but we managed to find good ways to get around everywhere without issue.