It's not. It is cheating. Let me explain..
In Windows 7 the hibernate function was disabled. Most of us would remove it and delete hiberfil.sys and gain back up to 10gb on the SSD. You had to, because SSDs were 32gb then. However, all they have done with Win10 is force enable it and you can't delete the hibernation file as it's now part of how the OS functions. So boot times are quicker, but only because it is using a pre made hibernation file. Which can also be really annoying, because it then opens everything you had open at the time it made the latest hibernation file.
Once into the OS it is no faster than 7. It may boot quicker because of this fat old file on your SSD but that is it.