Thanks for that. I don't think we'll bother. Puy du Fou looks great so I've just booked tickets for the one day it's open when we are there- and its a special cheap offer so thanks for the recommendation.
That's it really. Going to be in France in May. Fuuturoscope is about an hour and a half drive but as it is expensive I really don't want to waste the money and regret it if a 4 year old will find it dull. We will be staying near Saumur so any other suggestions gratefully received.