I remember Steve Jobs found it important to save 5 seconds on the boot of one of the first Apple machines, because you save lives.
How about a computer that doesn't need to reboot so often? I used most of the early Apple machines, Apple I and
The Amiga would be done booting up while the Mac was still thinking about whether the mac was happy or sad... You had to reboot it a lot, but at least it genuinely rebooted quickly. Especially if you had "a lot" of RAM, by which I mean an extra MB or so. Then you could put the whole OS (ROMs aside) into a recoverable ramdisk... talk about a quick boot.