I recently purchased a Garmin Rino 530HCX, it is a great product, I am having a problem using the peer to peer with the Rino 120, in a dense forest the position updates take longer than I would like but i dont think this is because of the 530HCX, its most likely the fault of the rino 120. It gets bad reception even at a 1/4 mile from a moving vehicle, and unless it has a clear pathway to the 530 it doesnt seem to update. I would assume that if both parties had the 530HCX the recpeption and the peer to peer would be better, this is a case of "your only as strong as your weekest link" and in this case its the 120.