It depends on the age of your kids and what they want from a holiday.Santa Eulalia isnt a good place for teenagers unless they can get in with a crowd at the hotel and make their own entertainment.There are not many noisy bars/clubs or amusement arcade type places so most entertainment is hotel based.We have been twice with 15 and 12 year olds who had a great time but mainly because they made many friends in the hotel and all mixed well together,we never saw them after day 3 of the holiday.
At the other end of the scale I dont suppose its everybodies isea of a great place for tots as there isn't an amusement centre with trampolines,rides ect as there is in Es Cana up the road.There is loads to do by day with great beaches and water things and boat rides.
If you are satisfied with a good hotel and entertainment it will be fine if you want loud "british type bars"there aren't that many.There are loads of bars though were you can sit and watch the world go by.
There will be loads of families at that time of year and if It would be advisable to hire a car and see the island of Ibiza,it really is a beautiful place
as for excursions we tend to do thing independantly and travl about on the frequent ferry boats that go up and down the east coast of Ibiza,I would suggest a ferry boat to Ibiza town as a good day out.
Which hotel are you in?
We like santa Eulalia because of its prettiness and has a bit of sophistication.