For us what we like the most is:
Cheaper housing (London compared to Adelaide) - we can actually afford to buy a 4 bed house here (we earn only $100K a year between us) which is 100m from the beach, in London we probably wouldn't have even been able to save enough for the deposit to get a 2 bed.
Better quality of life for our toddler - yes there were museums, but only 1 park nearby, our flat in London didn't even have a balcony. Here we walk the dog on the beach, lots of childrens parks nearby to play in, we can go kayaking, fishing, walking in the hills, go to wildlife parks etc...this wouldn't have been as easily accessible for us in London.
Fortnightly pay is amazing.
Getting money for your cans and bottles in SA
We have never had to pay for anything for the doctors (our doctor bulk bills everyone)
Cheaper public transport (compared to London)
A proper summer (41c) today - we don't have to take wellies when we go to festivals!
Getting paid overtime and having a 38 hour working week - I know this is just personal experience but most of my jobs in the UK had a 45 - 48 working week for average pay and no overtime, and some had up to 70 hours with the same.
There are lots of things the UK is better for though, and we loved London. Ultimately Adelaide is better for us as our little boy will have a better life here as we can afford a house with a garden.