We also went on Princess and were very pleased with everything from cabins to food to the onshore excursions and tours. You go through rain forest area along the coast so when we went in June, it rained all week. The week before and after were sunny, so you never know. Bring layers and waterproof jacket if you want to do any rafting or anything near the water. Bring a great camera for all the wildlife.
At the time, balconies were rare and we had cabins with balconies, which I'd highly recommend. The scenery of the glaciers is awesome.