All three different frequencies have different propagation characteristics. This summer I will be working about an hour and a half from my home (I'll actually be renting an apartment up there). The 28 MHz and 50 MHz radios are more for entertainment than anything else.
I can talk with locals on 144 MHz, and even the 50 MHz through simplex and repeaters. 50 MHz is susceptible to what's called "sporadic E" propagation, so it's possible over the spring/summer/fall that I could contact someone several states away.
28 MHz (10 meters) is HF, albeit on the upper side of the HF spectrum. It's not uncommon for me to make long-distance contacts on that band. From the Mustang I've made contacts with Germany, Italy, Puerto Rico, Costa Rica, Brazil, and Venezuela.
Also scattered across the country are 10 meter repeaters, several weeks ago I was talking through a repeater in Louisiana on my way to school.