Yeah, boot time, isolation (proper VM vs containers), and ease of use on a larger Hetzner box.

Did you notice a substantial difference in those factors between more traditional micro VMs that use OCI images (like Firecracker) and unikernels?

shorter cold-boot times.

If we’re talking about cold boot times, wouldn’t the relevant metric for unikernels be the hypervisor’s boot time?

How would that compare with containers running on Firecracker or other virtio-based μVM's?

A unikernel on Firecracker is probably going to start faster than a container on Linux on Firecracker.

I assume they meant using an OCI image for the rootfs of a firecracker VM, not running a container inside a firecracker VM.

Still difficult to see how the unikernel could be slower, but I doubt the difference would be huge? Don't have anything to back that up though.