We are thinking of moving to one of the above three towns. Price wise, they are all quite evenly matched. The commute is better from Berkhamsted and Amersham arguably, but we loved Marlow the most when looking round.
What I'm most interested in is the community spirit, the social scene and where our children (3 and 1 currently) would have the best upbringing - being able to involve themselves in local clubs etc?