grew up also and lived there with my own family until recently. great estate and community around there. Johnstown Primary school a bonus aswell. One of the best value/sq footage houses in the general dunlaoghaire/rathdown area. i presume a standard 4 bed semi you are looking at.
ballybrack is close by and watsons is in killiney, simple as that, and i've alot friends from ballybrack from childhood and there's no issues with either area. House will appreciate as good as if not better than other area's. on the commute, think there are express 7's and more bus options from cabinteely (not too far to walk). glenageary dart station is a bit far (about 15 mins) but still doable.
alot of sport options for kids aswell, with kilboggot park down the road.
So just go for it in my opinion.