You should start compare when the window logo started to come out because different motherboard have difference POST time.
An SSD would take around 10 sec, while a hdd will be around 30sec up to 2 minute depend on the software installed.
beside that, smaller hardisk will boot faster because the file was much easier to access compared to bigger hdd.

Not really wrong at all, just not enough details.
I think he meant partition.
Yes, the smaller the partition, the faster it is.
Samsung SpinPoint F3 1TB, make it 300GB(Empty spaces let it unallocated) vs WD Velociraptor, Raptor will lose.