Similar ish story here.
DH and I are both Irish and were living in the UK a similar length to you, OP. The Brexit vote was the last straw that made us want to leave and we came back when our 2 DC were early primary and preschool age.
All in all, it's been great.
School was a big factor as we far prefer the Irish system for a variety of reasons. I shortlisted schools by preference in the approximate area we wanted to live (multidenominational only - we didn't want religious) and prepared to go through them one by one to ask about available places for DC1. As it happened, we got a place in our first choice, and then chose where to live based on that. We moved mid year and DC2 started in the same school the following September. The school is fabulous and the kids are happy so I'm delighted on that score.
We had to rent at first while we sold our house in the UK, and it took us a good while to find somewhere suitable. Then the rent was twice what we would have paid for a similar house in the UK... but at least we were braced for it. There were a lot of hoops to jump through before signing the lease that felt pretty invasive, like providing payslips and employment contract as proofs of income, but luckily we didn't need to provide references when we explained we were moving from a house we owned. We had everything sorted before we moved over so were able to pick up the keys the day we arrived.
The life admin takes up a lot of time at the start, like applying for PPS numbers for the kids, filling out endless forms for bank accounts, being allowed to reregister our (old) car without being charged import tax, trying to understand and select a health insurance policy, etc. I remember changing electricity supplier purely to get a letter from a utility company to use to open a bank account..! But you get through it and the more preparation you do in advance, the easier it will be.
Oh - and I strongly suggest getting something like a (UK) Revolut account before you move because you can hold currency in euro as well as pounds - at a very good exchange rate - and use that card to pay for daily expenses until you have an Irish bank account sorted. It was a lifesaver for us just for groceries, petrol, etc.