Theoretically, on paper, MURS is a better choice due to the lower frequencies - HOWEVER, in my head-2-head testing, it was not much/if any better than GMRS. I assumed because of the additional power on GMRS.
HOWEVER - i have not done much testing in THICK forest or anywhere chock-full of vegetation, because we don't have that were I live so i defer to anyone with better/more data.