I too have been to Castle Hedingham, but unlike some of you, unfortunately only once. It is a georgeous keep.
I could almost see the medieval ladies and knights walking up the spiral staircases, so many feet that they left indentations in the centers of the steps. I also looked long at the Earl's and his lady's bed alcove off the main room on the 3rd or 4th floor (can't remember which), and wondered about all those ladies sleeping in one huge room on the top floor.
One thing I abhored, though, was that someone, probably in the 18th or 19th century cut huge double doors in the side of the ground floor, so that they could park their carriages inside the keep.
I have photos I took of Castle Hedingham, and would be glad to share them with others who descend from this family. Genealogy is my hobby, and I do not charge anything for sending out stuff to other genealogists (I have my own copy machine).
I also bought two books about the castle and the de Veres while I was there. If you are interested it obtaining copies, you could write to Castle Hedingham, Essex, Great Britain. I am sure there is an address on the Internet. The book and booklet were:
1. The de Veres of Castle Hedingham, by Verily Anderson, (Terance Dalton, Ltd., Lavenham, Suffolk,1993)
2. Hedingham Castle, English Life Pub., Ltd. Derby, Great Britain, 1995)
They both have lots of photos and drawings in them.