Hello,
Interested in thoughts on how best to choose a category for a cabin guarantee where you will be most likely to receive an upgrade. For those of you who have booked as a guarantee AND received an upgrade: What strategies did you use to choose a ship and category where you felt a guarantee would turn into an upgrade rather than ultimately receiving the same category that you booked?

Are there certain cruise lines which tend to upgrade guaranteed rooms more than others?

Did you receive more than a one category upgrade or is a one category bump the norm?

Are ships likely to upgrade you to a higher class as well as a higher category? For example of class, the Queen Mary has Brittania, Queens Grill, Princess Grill.

Any other thoughts?

Thanks.