Anyone here have any experience with a Datto Backup Appliance?

I have just been told that they've never run a full restoration in the six years that it's been in service, deployed for the backup of four mission critical virtual Windows Servers, four Windows Workstation and a (physical?) Linux PABX server.

The actual appliance is apparently a "Datto S3-2000 BCDR"

Edit: The anal retentive in me is going WTF in a tight loop. The industry professional with 40 years experience in the field is going, different day, same old...

I realised that I didn't actually ask the pertinent question, the hamster wheel was running full tilt, but is this normal, or is this WTF, or somewhere in-between?