I've done it several times, hence my name on here. I've always felt like a foreigner, like I never belonged anywhere, so I spent 5 years making it a reality.
What did I discover?
You can't run from your problems. The window dressing changes, you gain some valuable life experiences, but in a lot of ways it's same shit different pile. If you're going to do it, make sure you're running to something, and not away from something.
The main benefit to doing it is that radical change can re-activate parts of yourself that have been passive or sleepy because of whatever rut you're in. It feels like being brought back to life. But once the honeymoon phase is over and/or the culture shock of wherever you go sets in, you can easily sink back into the same habits as before. Which is why, during the period where everything feels fluid, fresh, and new, you have to focus on renewing your internal world, and not just living up an external change. Make sense?
At the end of the day, I discovered that my tendency to want to move was because I was running from my own problems. It was by forcing myself to stay put no matter what, that I finally faced my demons. I'm still facing them. It's a long-term process. But sitting still is the best way to start gaining perspective. Radical change can also be a BIG distraction from really facing yourself - or, it can be exactly what you need.
Another thing to consider is... the people you want to cut out? They hold your history, especially your family. Unless they are super unhealthy or dangerous to be around, I would think twice about it. Sometimes distance + time makes the relationship better. But if you cut someone out completely, you might cut off a way of learning about yourself down the road. Just a thought. Mind you, people come and go regardless of what you want. You've got no control over that.
Let me put it this way. Wherever you are, is your mirror. So the location doesn't really matter. How you relate to your outside world is a sign of how you relate to yourself. Changing locations will not change the reflection.
