MURS would work a little bit better compared to a consumer FRS/GMRS radio.
Most of the FRS/GMRS radios, while operating on a GMRS channel, are barely putting out 1 watt ERP from their stubby antennas.
A good MURS radio will put out 2 watts into what will likely be a slightly more efficient antenna.
Depending on where you are, 2 watts VHF will work better that 2 watts UHF. Been there, done that. My family runs a lot of UTV's and ATV's, have been for about 15 years. When we first got into it, I was the only one with an amateur radio license. Since I couldn't get others to get their amateur licenses at the time, I got a GMRS license and used that.
We mostly had 4 watt commercial UHF HT's, Motorola HT600,s P200's, HT1000's. They worked pretty well. In the mountainous terrain we ran in, UHF tended to bounce around enough to work.
Eventually I was able to get everyone else to get their amateur licenses. We went to 5 watt VHF HT's on the ATV's and 50 watt vhf mobiles on the UTVs with properly mounted antennas.
Even with just the 5 watt VHF HT's, we got better coverage in the forests of Northern California than we did with the 4 watt UHF HT's. It wasn't the 1 extra watt, it was the longer wavelength tended to work better in that environment.
Now with the higher power VHF's, we can get anywhere from several miles to several tens of miles when out on the trail.
Considering all that, I'd say avoid the FRS/GMRS radios IF you can find decent MURS compatible radios.
FRS/GMRS does sort of have the benefit of being widely used, but with so many of the radios running PL or DPL, relying on one to call out in an emergency would likely be met with disappointment. Of course the chance of reaching someone on MURS is probably less, but at least you'll get some better range.
Trick is, of course, finding a good MURS radio.
An ideal set up would be to have GMRS in use for everyone, and have at least one of the machines set up with a mobile or at least commercial quality HT with a decent antenna. That'll greatly improve your range.
Finding some of the older Motorola HT's that are grandfathered in under the MURS/Part 95 rules would be best.
Short of that, a good couple of FRS/GMRS radios would be much easier to find. If you could, get your GMRS license and set yourself up with a commercial LMR radio so you have at least one good radio in the group.