My DS has just started secondary and we are happy with it so not considering a different school, but I was wondering if anyone was considering the new one (Nord Anglia International School). It does seem hugely expensive compared to other private schools, especially considering that it doesn't have much of a campus. It's in Sandyford so tucked in among office buildings and blocks of apartments, I can't see how they could have much in the way of PE facilities (pitches for rugby/hockey/football/cricket or tennis courts). But I can see that the International Baccalaureat could be appealing to families that are on the move between countries regularly, or who expect their DC to go to university outside of Ireland.
I'm keeping my fingers crossed that DS doesn't find out that Irish won't be compulsory there, he's desperate to give that up. 