Thank you so much for all of the replies so far. Its been great to hear your stories. Each post makes a good point and gives us something to consider.
When we came back to the UK we moved to a location that was about 2.5 - 3 hours from where we were from originally. We found that our friends stayed in touch less or make less of an effort. We hear from our friends in Australia more than we do than some of our friends in the UK. We formed some good friendships whilst we were over there, being an expat immediately gives you common ground with others there and it felt like an extended family. We also met some awesome aussies, I find the people there very friendly.
We have been back in the UK for nearly 2 years and for most of the two we've been longing to go back and planning. There were short periods of time when we lived there that I wasn't FIFOing and it was great. Towards the end, when we'd handed in our notice at work, we were walking home from work in the sunshine and said to each other "are we doing the right thing going back?" and we decided that we were because the UK was home, we were only in Aus to work and that working and living in Perth wasn't the regular working week as I would be FIFOing. If I go back I would only consider a role in the city, otherwise there'd be no point. I think we also didn't allow ourselves to settle or try to settle as we knew we were going back.
I think you're right Booma, it took coming back here to realise what we wanted.
For those who came back to the UK and stayed, other than family, are there other things about the UK that you think make it a better place to be?