I'm like Frenchie, though for not quite as long. I am vehicle agnostic, which means I would go out with a lot of varieties of 4x4 clubs. Jeep guys all love CB's, Land Rover guys almost exclusively used FRS, and any one serious about the sport or serious about being a trail leader had HAM license setup
CB's can be extraordinarily frustrating. Sometimes with distances shorter than a thrown rock, depending on the set up, tuning, ground plane, battery config, cloud cover, solar activity, amount of iron in the rocks, I don't know. CB just sucks....unless it doesn't. Then its amazing and wonderful and oh so much better than FRS. But usually it sucks.
FRS is pretty good. unless you have a large group that gets spread out and the trail leader needs to designate a "relay charlie" to maintain the comms string all the way to the tail gunner. Other issues is that there's always someone with a hot mic (stuck PTT switch), or someone who's volume level is non-existent and can't be heard, or someone who simply can't grasp the concept of answering with more than one syllable words, and waiting for the noise cancelling to sync, and all you hear is "....elp. click/beep". If you use FRS, you have to push to talk, wait half a second, and then use polysybollic words, like "That's confirmed" instead of "yes", but all anyone will hear is ".....s. click/beep". Range with FRS is extremely variable, from "well thrown rock", to "line of sight near the edge of the horizon" (about 8 miles on a flat dry lake). Other issues is that there will always be that one guy with a fossil of an FRS, that has no sub channels or GMRS channels, so you need to stay on a common band, like channel 11, and you get every freeway wacko or inarticulate kid who's mouth is too close to the mic and they ruin your chances of communication. did you know that the higher channels put out more power? I forget the values, but it's something like 1-11 are .3 watts, and 12-21 are 1watt. That makes a big difference in range and clarity! As trail leader, I keep a nylon padded pouch with 10 or so decent FRS radios in it, using standard batteries instead of rechargeables. I think other than my rig, keeping a supply of powered up FRS radios on hand has been my biggest expense as a trail leader over the years. They just disappear.
HAM is the bomb. Simple test, maximum range and clarity, numerous abilities to extend range and communication parameters and methods. I am not a HAM hobbyist, and found it needlessly difficult to use many of the HAM radio units, but the effectiveness is inarguable, and the low cost of entry thanks to the cheap Chinese models make it so that everyone really should go HAM. But there is a learning curve. Not so much about HAM, but the radios. I would use my radio once a month or so, and would find that over the intervening 4 weeks I'd forget how to use my radio...that happened a lot! The user manuals are no help. They might describe how to engage a function, but not WHY you would want or need to engage a certain function (ICOM, I'm talking about you!). But once you figure it out, there is no going back. Everything else is so inferior as to be repugnant.
No matter what system you use, it is crucial to have a tail gunner with a good radio in addition to patience, experience, and leadership skills. You can usually count on a HAM user to have those requisite skills, and they are immensely appreciated by the trail leaders!