SPOT satellite transmitters are popular among our group, and don't need much introduction. See: http://www.findmespot.com/
Battery Lifetime on New Model SPOT vs. Original Model Spot
I was looking at the SPOT website this morning, and noticed that the new model SPOT has a significantly lower battery lifetime - only 20 to 30 percent of the original SPOT's battery lifetime. The new SPOT's tracking mode lasts only 4.3 days on a set of three AAA lithium batteries. The original SPOT can run in tracking mode 14 days on a set of two AA lithium batteries. The new SPOT can transmit 350 OK/Check-in messages on a fresh set of batteries vs. 1,900 on the original SPOT.
I would still recommend a new model SPOT over the original model because of its improved ease-of-use, smaller size and weight, better message reliability, and other new features. If you buy a new model SPOT, be prepared to change batteries 3-5 times more often than the original model. You may want to pack spare batteries with you on trips.
The original model SPOT is still widely available at significant discounts. There has been no announcement about phasing out distribution of the original SPOT units, but I believe it will happen soon. SPOT announced that there will be an upgrade path for owners of the original model, but details are not yet available. In my opinion, SPOT will continue to support the original and new models for many years.
Roadside Assistance Pricing
If you purchase the Roadside Assistance service the price may be a little misleading. The price is $30 per year. (When first announced, it was $50 per year.)
If you already have an active SPOT when you buy the Roadside Assistance service, then the website bills a pro-rated amount, set to expire on the same day as your other SPOT services, to keep them in sync. Some people may be fooled into thinking that the plan cost is very low (say, $1.50 per year), when in actuality it means that their service renewal date is coming soon.
'Hope this helps.