have to say the SPoT is best bang for the buck next to beacon.....
who's to say who is foolish, some of these are personal preference/riding style/area driven. if you can afford all of them, awesome. if not, you have to prioritize. rhino is great, but much like a beacon....not much good without others using them as well. SPoT can be good for the whole group, even as a single unit.
Spot has a long way to go but its another great tool and I agree with you that it is good for the group but the rhino has way more features and most in my group hunt as-well as ride and we all have them for multi purpose reasons. Some day we will have it all in one, including sattelite text. How cool would that be..