My only hesitation with the synology is where the company is going with their routers.
They don't seem to have AX wireless router in the works. That means they have only two current routers on the market.. one of which is a chopped down version for use as AP primarily MR2200AC. This is not suitable for backup.
The RT2600AC is still a good solid unit and well and truly debugged. It is expensive. But Asus for backup leaves me with ??? if you get to Catalina.. since major changes are afoot at MacOS.
(3G) airport base station with internal drive.
I sat for a min wondering if Apple ever released a 3G router. None that I know of. 3G usually refers to wireless for phone system.. somewhat overshadowed now by 4G and 5G.
So what you have is a Time Capsule with a 3GB hard disk. Is it Gen4 last of the flat box models or Gen5 which is the AC model?
Let me suggest a Time Capsule still has a redeeming feature. If you ever get to the point of needing a full recovery, only the TC will appear as a possible source. Apple made it rather difficult for any 3rd party NAS or Router with USB drive to work.
You can plug it into whatever router you buy and use it purely for backup. It might be a DIYer' dream but don't throw it away.
If you combine it with a normal USB drive plugged directly into the computer and using Carbon Copy Cloner might be the better way forward in terms of cost effective backups.. until the TC dies.. perhaps Apple by then will have another solution. It is interesting they have stopped production of Airports and Time Capsules but they have no iCloud solution for Mac backup.
