The number one complaint I hear from those forced to use Windows is that it takes forever to boot.
Then they're doing it too much.
It takes about 45 seconds for my desktop to come up from a cold boot to login screen, and I have not yet sprung for an SSD. This is long enough to be mildly annoying, but not nearly long enough to get up and do something else. My laptop takes more like three minutes, but it's a 1.6 GHz E-350 (2 cores). It's still not a huge problem because the desktop just gets put in Sleep mode and the laptop runs continuously (I have several services running on it 24/7 in addition to using it to drive a TV). The laptop typically gets rebooted once or twice a month, and the desktop about once a week unless I'm screwing with it in some manner.
Admittedly painful is the startup time of my Aspire One (especially on battery power), but that is almost relegated to the level of "toy PC" these days.