Anyone have tips on Alaskan cruises? Specifically Princess 7-day cruise from Seattle.

My husband and I are looking at booking this cruise and would first like to hear any suggestions/tips from our Fluther friends. We were thinking of definitely getting the room w/ the balcony so we don’t have to go to the deck to view every time. We were considering May 2011, but there’s only a 39% chance of sunshine…. so maybe September w/ a 53% chance would be better. I believe those are the cheapest months to cruise Alaska, and even then it is over $3,000 per couple including the flight. Also, any insight on the shore excursions?