So far we've had good luck with beacon call-outs. The cases we've responded to have almost entirely been folks that were legitimately stuck or lost, and yes, they were somewhat under-prepared for the situation they were in, but that's just the modern reality of outdoor play and it makes no more sense to expect all recreationists to be perfectly prepared than it makes to expect all software developers to build some idealized unit-tested software.
I have heard from other SAR groups that the beacons have been a mixed bag, and they're getting too many call-outs from people who just got tired and want a ride home. Those people deserve a verbal chewing-out from the local coordinator, but on balance I'd still rather everyone go out with beacons and have a good time and hit that button if they need to.