nevergoogle, - in my experience that will be the only thing that changes.
My dd1 turned 4 in the June we moved to england so started school full time (reception year) in the September. If we had stayed here she wouldn't have started until the following year.
She did reception, yr1, yr2, yr3 (three quarters of yr3) in england. Was always kind of bottom groups. I was hoping when she moved back up here she might have been in the middle groups in her class, as the children in school with her now in Scotland have done a year less than her. Unfortunately she is still in the bottom groups.
Dd2 started school last august here in Scotland. The teacher has told us she is very bright etc. yet her reading books, and in fact all the class's reading books are very low. Children were finishing reception class in england on much higher levels that the kids in the p1 class here.
I had lots of people tell me that reception year in england is much like nursery but I don't really believe it. Dd2 has done much the same stuff in P1 here as Dd1 did in reception in England.
Oh and I was still doing biff and Kip with dd1 in her yr3, but some kids were free readers by then.