I did it out of curiosity. I used a StarTech 2.5”to 3.5” drive converter/enclosure. It is exactly the size of a full HD, no bevel recesses. You would need to demolish the rubber padding in the time capsule. I feel like a dremel cut on the StarTech enclosure would make an easier fit. As far as backup speed, a ~300GB first back up reported a 2hour completion time. Whereas the traditional HD was something like 6. This was over Ethernet. [br]
I’m eyeballing a 4TB WD Red NAS SSD. This is unless some better option comes along, price vs. storage. I’ll do a guide, if that happens.