"sigh"..........Nothing about being "too cool", there is a place for everything. In international operations it's appropriate. While on center or departure where you are already established in radar and radio contact, not necessary.
In my professional career I've had about 6 times I've declared an emergency. One was while being oceanic, the rest were in ATC contact. Just made the call, told the controller I was declaring an emergency and why, then proceeded to take care of the problem. Nothing was unclear, no one was interrupting and everything went smooth.
I can't remember the last time I've actually heard anyone using it on frequency in the states.
"sigh".............. (LOL!)