Jack of all trades vs master of one, and terrain
Emergency Locator Transmitters are marvelous things, but the infrastructure to support a truly excellent one is fantastically expensive. As such, the world actually got together on something, and built one system called the 406 MHz ELT. Everyone uses it - ships at sea, jetliners, and hikers willing to throw down the ~$350 for a transmitter able to share the playfield with 747's. There's a jointly run NOC that knows how to reach all the world's emergency responders, from the Eritrean Coast Guard to CalFire. This system was conceived in the 1980s, so it doesn't think about mundane uses like tweeting, and in fact is not 2-way.
The 406 system has one job and one use. It has a long life, one-shot battery, so it doesn't need to be occasionallly charged like a normal electronic device.
There is a private effort called SPoT, which is less optimized to be an ELT and more optimized to be a social media toy. It uses the Iridium sat phone network, which is intended for satellite phones not emergency locators. As such, Spot's coverage is poorer than the dedicated 406 MHz ELT network. By "poorer" I mean ability to function in valleys and canyons, and also ability to communicate with more obscure emergency services.
However, because SPoT is rooted in newer 2-way system, it has some bells and whistles the 406 MHz system does not have. It hourly logs your location, creating a "breadcrumb" log of your route (when able to communicate) or when commanded by the user. And of course, it has its primary function of 2-way messaging, which you can do anytime you have signal.
SPoT is also a pay service, which means you must have it paid up, and it has an ordinary rechargeable battery that must be recharged every few months at least. You can,t just stick it in your glove box for a rainy day.
This equipment can also be rented. Emergency responders call the owner, who states who they rented it to. (Of course that's a link in the chain!)
This is a corner case, though
Because he was in a crevasse, he's more likely to get signal from a 406 MHz ELT than a SPoT, but realistically there's a fair chance he wouldn't get signal for either one of them. In that case, each of them would contribute something different.
- SPoT would contribute the "breadcrumb" locations from the hours before, which would get them within a couple kilometers. That's if authorities could associate his 911 call with his SPoT account - and that's a big if!
- the 406 MHz ELT has a second trick: it transmits a tone on the 121.5 MHz emergency frequency, which is an older, pre-satellite emergency location system designed to direct terrestrial rescue efforts. It is used and monitored (not least by passing airliners) and emergency services are well-practiced at triangulating on signals from it. Ideally, 406 gets them in the neighborhood and 121 brings them home. There's also a chance his tone would be heard organically, even with a 406 failure due to terrain. If he had specifically said on the cell phone that he'd activated an ELT, they surely would have sent a plane up and down the coast to listen. They would have triangulated quickly, between the tone and the verbal description "I can see the ocean".
Again, this is a corner case. On an average activation, especially assuming terrain is involved, the 406 is better than the SPoT, and certainly works more places in the world (because the 406 NOC is better equipped to reach relevant authorities).
I am also concerned with cases like James Kim. SPoT requires you keep a subscription paid up and a typical smart-device battery recharged. If either of those is let to slide, SPoT is worthless. A 406 can be thrown under the car seat with the flares and poncho, and forgotten about for several years.