Audiovox claims that its GMRS7000CH model two-way radios have a seven-mile range. Living in Manhattan, it's hard to judge distance (seven miles is more than half the length of the entire island), so I can't testify with certainty to how accurate that range is.
I can say, however, that I could hear everyone I talked to on the radios with total clarity. Admittedly, given the fact that my apartment, office, gym, and friends' apartments are all within walking distance of each ...