We have done 15 cruises, 9 of which were on Princess. In 2008 and 2009 we sailed the Diamond, first to Hawaii R/T LA and this year Auckland/Sydney.
We did not have, nor have we ever had, problems with the Princess staff. That's one reason cruise 16 is also on Princess.
However, I also don't expect the staff to grovel at my feet whenever they see me. Sometimes I think it's expectations that get in the way of our views of things, rather than what actually happened.
I'm sure that a number of people have had bad experiences on Princess as well as any other cruise ship, including the most expensive ones. We had staff on Princess, and other cruise lines, that were less enthusiastic than others, but that does not mean they did not do a good job for us. In addition, I think they are entitled to have a bad once in a while. I would too if I had to work the days and hours that they do.