The radios that have the 5 mile range are commercial radios - like contractors use. They are very bulky and the licence part is true.
I have TalkAbouts - can't remember what model - but they have subchannels, but no vibrate. I really wish I had the vibrate, because there are times when the surrounding noise makes it tough to hear, and I think the vibrate would be hard to miss.
I haven't had problems with interference on the line, but I think more and more people are getting them. My first trip with them, I hardly noticed a soul with them - but the last trip was a different story.
Also - try and find one that has a feature where it stays on a low-power mode until it's buzzed in on. That will save you a lot of batteries in the long run!