We have cruised a lot in the last 2 years. Princess is our go-to cruise line. The Island Princess only has one major fault - they closed off the promenade deck at the back to add more cabins, so it's not possible to walk all the way around deck 7.
The shows that we went to were mostly very, very good and interesting (a harmonica player that blew us away (oops, bad pun) and the production shows were Broadway quality - the 4 main singers were all very good.
The evening menus were not as diverse as we've experienced in the past. That said, all the food was well prepared and very tasty. The horizon court was fine, although there were some shortages here and there (ran out of cottage cheese, yogurt, lettuce, some fruits, etc. at times, for instance). And again, more diversity would have been welcomed.
Could use new couch, and new hair dryer. The balcony furniture on this ship and all the others we've been on, is very uncomfortable. Otherwise, all good. Our steward, Gerald, was amazing.