As XPLORx4 & Mookie mentioned it's great to have in the truck.
I didnt really want one at first - and got a handheld one... it was soon after when the crappy reception lead me to buy a proper unit for the pathy. I have kept the handheld, as we use it on the trail when out of the truck, or lend it to the new guy with no CB on runs...
I installed mine before I was even offroading -- mainly for trips with SOXC, as everyone chatters on the CB, and it helps the time go by. Also - like the others mentioned, on & off road it's good to have communication throughout the group. It's nice to have even when I'm on my own, as when traffic gets bad, often the truckers ahead will let you know which lanes to get in, or to get off the highway if it's really backed up.
Also, it's a great ego booster - LOL, I've gotten a few compliments about the truck on the highway. (Yesterday even!)