Such a telling report:

Part 1: "Last night, shortly after 9:00pm, the Sheriff's Office received a 911 cell phone call from one of the hikers who advised that she, her mother, and two other females lost their sense of direction due to thick smoke from the Aspen Creek fire.

The phone call continued to drop but, with the use of the phones GPS, dispatch personnel were able to get an approximate location on the John Muir Trail between Lake Italy and Bear Creek.

...SAR personnel are currently being deployed into the area to search for the hikers.
"


Part 2: " In the second incident, at about 10:00am, the Sheriff's Office received a report of a GPS emergency "spot activation" in the area of Lake Virginia, approximately 10 miles north of Lake Edison in northeastern Fresno County.

The Sheriff's Office learned that a father and son were hiking in the area when the father started having serious medical issues.

H40 responded and was able to extract the ill hiker.
"

In part 1, they're out looking for missing hikers. In part 2, due to a SPOT, the problem is already resolved.

Seems pretty clear to me how much better it is to hike with a SPOT.