No it's not a good thing. Trying to control vessels have been repeatedly tried throughout Chinese history and it's proven to be a bad idea each time.One has to respect the degree of control the US manages to exercise over its "allies." China should learn from it for, in the future, when it will have similar opportunities to gain "allies" of its own. It is quite extraordinary how the US can manage to get Europeans, Canadians, Australians, etc. to act against their own interests, and be content while doing it.
If the vessel is weak it's just a drain on your resources because they will constantly beg for stuff
If the vessel is strong and has ambitions then they will plot to backstab you at the worst moment
That's one thing that US doesn't understand about the relationship between North Korea and China. When discussing nuclear weapons on the peninsula US would go "China rein in your dog and I'll rein in my" and China would go "you don't understand, I can only put in a good word for you and make suggestions, I can't force them to do things - they are their own sovereign nation."