Let me start by saying, I like Royal Carribean. This was my third cruise with them, Likely, I will cruise with them again. However, on this cruise I discovered that sometimes a cruise does not live up to expectations. Such was the case on my Alaska cruise. There was one major issue with this cruise. And that issue was exteme vibration in some of the Junior suites onboard Rhapsody.The problem does not effect all Junior Suites on Deck 8 apparently. Only some of them. I did some onboard research and here are some data points:The Junior suites having this issue are on the starboard side (right side of the ship) towards the back of the ship. Didn't really investigate the Port side for this problem.Cabins in the ranges 8550 - 8580 plus or minus a few cabins have the issue.The vibration is extreme. Although I have not been on a freighter or cargo ship, this level of vibration in the slepping quarters may be acceptable for those types ships. But for a luxury cruise ship and upper category cabin is is definately unacceptable. Unless you can sleep through anything or intend to be well sedated when you go to bed, these are not the cabins for you! The vibration is in the range of several inches up and down. It is in no way suttle vibration that is felt in other parts of the ship.The extereme vibration ony manifests at lower ship crusing speeds. At faster cruising speeds, the vibration is insignificant. Unfortunately, on the Alaska cruise, the ship mostly cruises at the lower speeds.We complained and were somewhat begrudgingly given another lower category (cramped) stateroom. But it was far better than enduring the bumpy ride in a Jnr Suite.Otherwise, the cruise was satisfactory. Alaska is beautiful and helped make up for the disappointing cabin experience.