TrvlPro--Thanks for the heads up on the bunk beds issue. I have another one to add: STAIRS!
We usually book Guar. Rate and have had some very nice upgrades, especially 2 on NCL Sun from Inside to Oveanview... but one of those rooms was on a deck that was a half-flight of stairs between decks 6 and 7 called deck 6A. It was fine for us but we didn't know ahead of time and it could have been a disaster for someone else. If we got bunk beds we'd just laugh and have a good time anyway but we're able enough to put up with it, and for someone else it could ruin their vacation.
Carnival also has a lot of ships with bunk bed rooms but I think all are in the lowest catagory.
Yes! We must do the homework first to investigate worst case senarios for a given ship if we're going to take a pig-in-a-poke cheap rate with a Guar. catagory and be aware of our limitations! But it can be a big savings and it allows us to take longer cruises for the money. On the NCL Sun we did a back-to-back and sailed for 2 weeks for $100 more per person than what a balcony room was going for. It was great even though we had to change rooms at the end of the first week. I'd love to do it again...but not booked on anything yet this year, yet...