Not only do the Garmin Rhinos have good radios but you can poll your partners on your own screen and it will show you their location without calling each other. Works great, I took a newb with me a few years ago and put him on a stand. After a couple of hours he was up and on the move, called to see what was up. You can also text / send messages but I have not used this feature. If you want to stay connected they work.
Plus a great GPS.