Do they really heat water faster?

Yes

How would you regulate how hot the water gets, either boiling or on
the brink of boiling? (usually I let the water rest for a few minutes
before steeping senchas, whites, and other delicate teas)

I listen to the sound.


As a side question, do you measure how hot the water gets before
steeping your high quality loose leaf teas.

Infrequently