Yes it is definitely worth a visit. The stones are impressive. But try and do so in good weather (difficult when you have to book in advance) and when it is not too busy. The visitor centre is a bit away from the site itself, but they have free buses to take you there if you don't want to walk. However the walk is very nice in good weather. The visitor centre is a bit disappointing compared to other sites eg the Giant's Causeway with fairly limited explanations for children.