My experience with incremental backups is that on the whole they are now the same or almost the same size as "full backups" with Vista. Take my own case as an example - I have a full image backup with the scheduler set to do weekly incrementals thereafter. The full backup file is 61.4 gig and the incremental has just completed and that is 60.9 gig. As far as I can see the reason for this is that Vista performs low level defragging also once a week hence the files are constantly being rearranged hence Acronis having to make an almost total new build every week. One would have thought that Acronis might have realised this by now given that Vista has been on general release for almost 2 years.