I know I still run 75mhz on some of my older cars when bashing, and there are days when there are "dead spots" in reception. It's usually less than 100 feet away from where I am standing. If I make it through that dead zone, the receiver works well. But passing through it, I lose most control. Other days, there are no problems.
So don't forget about good ol' rule 15 of the FCC regulations.