It depends what you are looking for.
The DHF would be more useful all around for people in Quality, Regulatory, Supply Chain, and even Product Development. This is because this will provide more then enough information for all the departments to satisfy whatever needs they may have at the moment. I believe it mainly comes down to what the project is and how large the scope of the project is. For example, if you are in Regulatory and doing BSI changes for 100 products that are similar, then the Tech File/Design Dossier should be sufficient in terms of acquiring most of the necessary information needed. If you are in Product Development or R&D and managing a project for a single product, then the DHF would be more useful as the scope is just one product line and managing that information for that single DHF would be more manageable and most likely useful.