I think it depends on why you move, in general (war and oppression etc excluded) if you are unhappy at home you'll be unhappy abroad IMO. If you move to get AWAY from your life it'll follow you (you'll have similar relationships, similar work problems, similar debt etc), but if you are okay at home but move TOWARDS somewhere you feel more of an affinity to then it can be wonderful.
It also takes a few YEARS for a new country to be home
I was happy enough at home, but sort of always felt a bit like how people describe being born in the wrong sex feel, I always felt my life was happening without me in the UK, so I moved, and it is home, am more at home here than where I moved from. I get home sick for here if I go back there etc.
Now here's the thing that can confuse if you're trying to gauge the issue, if you went to the places where ex pats from my country congregate you'ld probably find that the majority, probably all, would say that it's not all it's cracked up to be. The ones who say it is are scattered and integrated and sometimes hard to identify.
It is same shit different town, it's not a permanent holiday, you still spend most the week at work, come home to bills etc etc. But I didn't move to get away from real life, I moved because I prefer WORKING here, I prefer dealing with companies here (hate the backhanded "who you know" way of doing things back "home") I prefer the daily grind here, the daily grind grates at "home". Days off are nice anywhere (well most places).
I've also lived and worked in America, I hated it, people always assume it was a big old holiday. I don't feel an afinity with American culture "under the surface" (class divide etc). Of course at the time (early 20s) if anyone asked my how it was I'ld say "oh it was AMAAAAZING" 
When it comes to Australia I think the proof is in the pudding. EVERYONE I know who moved there is back, despite saying how AMAZING it was and how they'ld love to go back "SOME DAY"
I think if it's truely right you don't call it "AMAZING". I don't describle life in the UK as AMAAAZING. There's good and bad, but more good and less bad than "home"
and if I had to go home for something specific, there'd be no "some day" about getting back, the UK is my real home and it's where I'm meant to be, I wouldn't be contend to file it away under "maybe some day".