Peter & Jan, I live in Dorset and by chance I am going to East Fleet next week end. It is a great, well managed, site with the camping areas set up in their own 'enclosures' so even if busy it dosn't appear to be. The toilet blocks are kept clean and more than adequate and the faciliies e.g. club and play park etc are good.
The views of the lagoon of Chesil Beach are great and good for an evening stroll. I am sure you will have agood time in a beautiful part of the country.
If there is anything particular you wish to know then please ask and I will find out at the week end. Ray