As a first time-cruiser who has yet to get on board, I have no personal savvy to offer here (besides coming in late). That said ...
Advice I got from a long-time cruise ship employee is this:
1. Waiters and cabin stewards have a "flock" of people to serve. Some are going to be great cruisers, others not so great, a few real stinkers.
2. Consequently, such service people are going to quickly prioritize all those whom they serve, especially on longer cruises (such as a week or more). And, one criterion they use is the "advance tip."
Conversely, really demanding and rude customers are probably going to fall to the bottom of the priority list.
As I'm moving into an era of life where I might be cruising (as I said, this upcoming cruise is my first), I'm going to try this and see if it makes any discernible difference.
This is likely too late for the original query, but I'll try to remember to come back and respond to my own post here, to report what (if any) conclusion I make.