Deems to me Demko has that quality that all top-tier starting goalies seem to have--the ability to block out the last goal and re-focus. They just let one in, but they're determined not to let the next one by them. He seems to make huge saves when the team needs them most.
This was also a feature of his play in Utica. For goalies it's now 'how' many saves they make, but 'when' they make them. And his calmness in the net seems to inspire confidence in his teammates. His puckhandling, which was always was a big part of his game in the AHL, will improve as well once he's on the same page with the d-men.
God knows d=men like Pouliot, Gudberanson and even Stecher and Hutton desperately need the kills of a superior puckhandling goalie.