You're so right. Different people on different systems is a PITA every time. Those little FRS/GMRS handheld radios are really only good for camp and spotting. Maybe car to car if you are very close. It seems like since the Midland MXT radios came out more and more off-roaders are switching to GMRS. The 15 watt model and an external antenna should be good for 3-5 miles easy. That' s a good usable range. Plus, being hard wired you don't have to worry about batteries and the antennas are so much easier. I'm likely going to install one of these myself so that I always have it available. I can use various handheld radios for Ham stuff but I don't want to have expensive Motorola gear in the Jeep. They aren't exactly secure!
It has been getting a tad bit confusing with Trail Rigs, everyone now using GMRS in addition to CB/HAM. Personally i have a Yeasu FT-1500M in my rig (well kinda.... still working on mounting it) to work the ARES net locally, and a Yaesu 50r/Radio Shack HTX-200 for handheld comms. Adding an under-seat mount CB like the Uniden at some point, I do have a Midland handheld. This translates into me receiving a message for the group from 2m and then relaying it over CB for those that have CB's, and they, in turn, relay it over FRS/GMRS. I guess if I was part of a local group that decided on a consistent radio plan, I would go with that, but I am not and everyone I go with has a different idea of what's best. I was going to put a dual band rig in, an FT-7800 or something, or program the 50r for GMRS/FRS on 440, but... honestly, it seems too much like work.
In a SHTF scenario, I plan on listening a lot more than talking, and ...... CB/HAM/GMRS all pretty much suck locally. So does Cell service. Very unreliable here. (Hey, Vermont has a lot of hills, and very little line of sight).
So I guess to get back on topic, I would respond by saying, find out what is used most in your area, and/or the areas you are traveling to. Pointless to invest in a high-end rig, only to find out everyone in the area is on CB. Most of my gear was purchased when I was active in the local Ham Radio club, and when I was interested in ARES/RACES/CERT. If your travels are taking you away from home to remote locations, then HF is the way to go, as well as a General or Advanced license.