I am aware of the file exclusion option.
That has the draw back of "part change, whole file backup".
E.G. If the user opens up Outlook and a PST gets edited the whole 5GB gets backed up again.
If you use full system image you get block tracking and only changed data gets backed up.
E.G. If the user opens Outlook and a PST file gets edited only the part of the data on the drive that changed gets backed up.
Down side is that if the user decides to put his collection family vacation holiday videos on his laptop (all 100GB of it) is effects the backup adversely (space used = increased cost of storage, time it takes to backup = decreased performance for server and user, incomplete backups if the user didn't stay connected for long enough).
Times this by a few similar infringements and I have my hands full just managing user backups.
With BitLooker we can exclude these media files and still use benefit of a full system image.