My 2¢
Here is my synopsis of this discussion, leaving out the 'tastes great', 'less filling' arguments:
(I probably missed some)
Personal Locating Beacon (one way alert), cost = $
--Advantages: simple to use, lasts ~5 years, pinpoints location
--Disadvantages: alerts SAR only, no communication with SAR/family/friends
Satellite Communication Device (Spot, inReach, et.al; 2 way text communication), cost = $$
--Advantages: texting capability, communicate with family/friends/SAR, pinpoints location, weather reports
--Disadvantages: not as simple as PLB, monthly subscription fee > $15, needs periodic recharging
Satellite Phone, cost = $$$
--Advantages: can use like regular phone.
--Disadvantages: does not give location, airtime costs, periodic recharging.
As I see it the lack of being able to communicate with SAR is a big negative; a completely different response is needed for "I hit a rock and punctured my oil pan" and "I hit a rock and punctured my head". SAR peeps can comment on what the response is when nothing is known other than location.
The satellite phone's lack of giving location to me is a risk. If I hit my head and am not lucid enough to relay GPS coordinates the phone is not much help. I don't know how easy it is to pinpoint a satellite phones location.
Since I travel alone I like the ability to keep in touch with my family. The inReach prerecorded message with map and pin is what I use most. Texting back and forth when needed has been sufficient and the ability to get a basic weather report has helped on a couple of occasions.
jim