I've been quietly relying on AASync for the last few years. It does it's simple task of backing up files flawlessly, without the need for any intervention and it does this with the minimum of fuss.
I'm responsible for I.T in a small but very busy advertising agency, we have a Mac Server and a PC server.
I use AASync on the Mac to mirror the various volumes I have on the server to usb drives. I have multiple syncs set up that run throughout the night and I rotate drives on a daily basis. Every morning I come in, AASync has worked, I swap the drives. It's been like that for years.
The ONLY issue I've had was a strange error message on a recently added 26Gb of data added to the server. I contacted Robert and he replied practically instantly. He pointed out the my version was 3 years old and I should upgrade. A free upgrade I might add, not many software companies still provide free upgrades to software years out of date. Upgrading also fixed the problem.
AASync is an absolute breeze to set up, unless you're mentally challenged, or under 10 years old you should have no problems setting up the sync.
I have to use Acronis and Symantec BackUp Exec on the PC, both of which are clunky, confusing, bloated and not user friendly, the complete opposite to AASync.
If I could rate it higher I would. If you need a backup on a Mac and don't get this, then you're an idiot.