DeLorme with same unlimited tracking with month to month activation is $35 a month. For myself (due to frequent use) the DeLorme service would be cheaper if I paid the $300 annual instead. That $200 increase and having to buy a new unit have kept me from switching over. But I admit the send and receive texting capabilities is a big plus when needed.
The month to month you speak of is their Freedom Plan @ $35/month, which enables one to suspend service and billing for the month(s) the unit isn't in use. To some that is a big incentive over SPOT in addition to two way texting.
A heavy user who want to keep service all year long pays $25/month with an annual contract.
The cheapest way to go, except for tracking, is to get the Safety Plan under a Freedom Plan contract. This is $15/month with suspendable billing but gives you a two way texting tool in your toolbox for when things go to crap in the bush. If you only take one or two big trips a year it could be the best money ever spent if you get into a jam.
For those who like tracking for their family and/or audiences, the best bets are the Recreation Plan either on an annual contract if you are a heavy user or the Freedom Plan so you can suspend service and billing if you're not traveling.
I have the Recreation/Freedom Plan structure and have sent and received a ton of messages on the Delorme which one can't currently do with SPOT devices.
I personally wouldn't depend on lack of movement from tracking tipping off family and friends to send EMS. Too many scenarios where EMS could be triggered when there was no need. And it could get $$$ if SAR assets were summoned by family when there was no emergency.
I really don't understand why parsing what amounts to relatively little money is so important with so much on the line. People go out all the time and blow what equates to fancy dinner money on the same relatively small amount it costs to have a unit in your pocket that will be your potential lifeline when you're in serious hurt.
Like I said before, SPOT knows it is in serious trouble with market share and is probably working desperately to come up with a similar unit and service. Even if they do, their problem will always be their inferior satellite system which can't hold a candle to Delorme's. In my book, and I speak from the experience of having owned every SPOT model to date, they can't even come close to the two big points of measure, functionality and coverage. Delorme has passed SPOT at full gallop and will probably never look back.