I think you are right about your son being too young for Disney. When we first went my youngest was 15 months and it was rather lost on her. All my others though - aged 9 to 5 at the time loved it and then we went again when they were all old enough to go on the bigger rides too and it was a fantastic holiday. We intend to go again sometime in the next couple of years, as what will probably be our last family holiday together with just us....after that I expect there will be BF's and GF's tagging along if not H's and W's with children. WE just want one last holiday together with just us!!!
I think evryone takes something different away from the experience depending on their age. For me, it's all about the childrens' enjoyment. If they are happy then I am happy.
With your son being the age he is, going away with his cousins sounds ideal.
Saffie me 46 H 46 M in 1986 D20,D18,S16,D13 H's A 01/05 to 07/06 H recommitted to M 07/06 renewed vows 09/06 Going from strength to strength