I have purchased the ACR ResQLink for work, and I think it is a very reasonable cost for the benefits it provides. I (thankfully) have never had the need to employ it however.
It is easy to use, being able to be employed with a single hand if needed. As for coverage, I don't really know anything beyond their marketing claims.
WARNING & DISCLAIMER:
SELECT AND USE OUTDOORS AND SURVIVAL EQUIPMENT, SUPPLIES AND TECHNIQUES AT YOUR OWN RISK. Information posted
on this forum is not reviewed for accuracy and may not be reliable, use at your own risk. Please
review the full WARNING & DISCLAIMER about information on this
site.