Characters and rigging are also the areas that I'm mostly interested in. So I fully agree with all your points... oh how I wish Xpresso was faster and would use the new node UI...
Anyway, even though these areas seemingly weren't touched, with character rigs of medium complexity I roughly got a speedup of 30%.
That's what I meant with almost everyone will benefit from these core speedups.
I still wish for more optimization and performance, but it's certainly a lot better than it used to be.