If you want to see a pro that has great Hand Held Mic Technic watch Johnny sing this tune from 2:30 till the end of the song!!!...
just a memorizing stage presence, what an amazing singer wow!!

I'm just saying a hand mic requires a certain amount of attention directed towards it because your voice has to go into it obviously. Pro Artists can use this to give certain nuances to performances in regards to the strength of their voice. A headset allows you to bounce around but you're not going to have any control over how far that mic travels from your mouth at any given point. It also can be annoying to wear for some.
That said can we get back to Nursing Home performing etc,etc, and how we can learn from each other.? just sayin'...