john smith wrote:
I have no way of knowing if anything has changed from my original
briefing until I land at my destination.

Well certainly, if a TFR were suddenly thrown up between the time
you got your briefing and the time you took off there would be a
problem. In fact though, the chances of that happening are probably
pretty slim and to my knowledge has not been a factor in any cases
of busted TFRs. Having gotten your briefing (which is documented)
your ass would be at least covered for an accidental bust in the
unlikely event they trew up a TFR over your area between the time
you got your briefing and the time you took off. If you are flying
XC a radio is an essential item, really -- IMHO.