Old thread, I know, but effective coms is a big thing for me. FRS/GMRS just underwent some rule changes recently. You do need a license for GMRS but it's $75, good for 10 years and covers your entire household.
The biggest advantage over CB is that FM is much clearer than AM. Your audio is much improved and there's a lot less static to deal with. You are also using the full power of the radio the entire transmit time vs AM where you only peak on certain syllables and waste 4W of your power on the carrier.
FRS and GMRS are different services but share frequencies and are interoperable. With this, a non-licensed person can use a cheap FRS HT to talk to a group of licensed GMRS users on a trail ride with no issue. FRS is limited in power but a GMRS license gets you up to 50W of available power and the ability to use repeaters you can get permission to use. That can really extend your range! A ham friend of mine recently set up a GMRS repeater in Roanoke and we've been playing with it some, trying to drum up some interest and see what kind of coverage we can get with it where it is to possibly look at relocating it up higher to open it up more.
I lobby for FRS/GMRS over CB in every group I'm in just because of the ease of operation and quality of sound. A CB antenna's resonant length is 106-108". A FRS/GMRS antenna's resonant length is 6" and you can get very efficient antennas that are about the size of a pop can. Just think about that the next time you're wanting to install a radio in your rig.
