Never tried Duplicati, but restic + B2 has been great as "a different choice", and for my use case of backing up a variety of OS's (Windows, Mac, and different Linux distros, anyway), it's worked great.
Restic and B2 "just work". Works how I expect it to, and restores what I expect it to. Not amazingly fast in backups or restorations, but it works reliable for me. I have restic running on everything from workstations and laptops, (~200G each), to servers (500G-2TB) to a mini 'data hoard' (25TB+) level of backups, and its been doing great on each.
I did not like and could not trust duplicati to finish backups or restore from them.
