We are an Aussie family in Europe. It was an easyish decision for us initially. The children were small, we were financially ready and there were some good job opportunities. It was made easier by having a sister in a near-by country (has now gone back to Australia) and by the fact the fact we are not particularly close to either of our families.
I did at first have the desire to stay in Australia and work on the relationships between us, our siblings and their kids, but our siblings had their own lives and weren't really interested. That was reinforced everytime we returned for a home visit. My PIL visit regularly, which we enjoy, and my parents don't, which I also enjoy.
Overall, it works for us. Our kids have integrated well, as have we, and we now see ourselves staying here long-term now, as in, until retirement.
It is difficult with family deaths, and we have lost a few family members whose funerals we didn't get to, but that is one of the sacrifices you have to be aware of and willing for.
Overall, we are happy we made the decision. Expat life doesn't work for everyone, and certainly have seen a few young families go back or go to another country for various reasons (cultural differences, relationship problems, lack of local support, missing family) after a year or so. Overall, I think it is worth trying, giving yourself a time-limit and reasonable expectations of what you all want and expect before you go. Better to try and come back than have regrets about not doing it.