I NEVER use the incremental backups. It can be too confusing and something is missed.
I have Acronis, but I don't know how their incremental works. Generally incremental only backs up what has changed or been added since the last incremental. When you do a restore from incrementals you have to first restore the basic (full) backup and then each incremental sequentially to have everything restored (and properly).
Where I used to work, when we first got LAN's and file servers we used the incremental backups (a full backup was done on Monday evening and then incrementals the rest of the work week). As it turned out if a server had to be restored it was (1) a longer time to restore and (2) if the incrementals weren't done in proper order it would mess things up. After a couple of fiascos the incremental was abandoned in favor of a full backup every night. The full backups took longer and required more backup space but it eliminated all the potential problems when restoring.