I don't get why my Dell laptop xps 15 with 32GB of ram is four times slower than my Asus Zenbook with only 8GB of ram?
Reboot is 30-32sec using Dell laptop
Reboot is 10-12sec using Asus laptop
If it sits at the splash screen for a long while, it could be trying and failing to initialize a driver. If you re-installed the OS yourself, are you sure that you took care of all driver installations?
Don't zenbooks run android? You aren't even comparing similar OS's. It's also not 4x slower. 32secs vs 15secs is only twice as long. If the laptop has more devices then the zenbook then it needs more time to load devices and drivers.
You can check the laptop to see if there are things you can do speed it up. Enable anything called fast boot, or disable ram or keyboard checks. Turn off anything you can't use. If wifi, firewire, or second NICs can be disabled, do it. The less your laptop has to turn on, the faster it should boot. If the 30-32sec figure includes the things windows loads, remove things from the start up. All this should cut down the amount of time you have to wait when turning on your system.