It’s really down to where you want the files to live. Sure synching would provide easy redundancy with a copy of the files on every machine, but that 20GB of documents or whatever would effectively become 100gb of files if it’s being synced to 5 different computers, eating up 20GB of space on every computer, meanwhile using a standard network share would give you a single centralized location with one copy of the data, then you just make backups according to whatever your backup scheme is.