If you prefer Zorin on live usbdrive, explain why

If you prefer using Zorin on live usb drive -- RATHER THAN installing it on a computer's harddrive -- please explain why that works out better for you. I realize that usb thumb/flash drives have limitations, but going the installation route has its own travails. Obviously, different persons' computing needs and situations, might make the usb drive a better option in at least some cases. If that's you, please tell more about your thinking and experience with this issue.

I've just ordered a ZorinOS 10 thumbdrive from OSDisc to try out on an HP ProBook now running that troublesome Win8.1 (arrrrgh!), so I am admittedly quite the Zorin pre-newbie, though I have dabbled with linux off-and-on for several years, mostly with some earlier versions of Mepis and Puppy.

Thumb drives are useful for security reasons as they run in memory without touching the hard drive, but the hard drive will still be accessible. Really a portable drive is just after it's name sake - for portable use. I use it on holiday rather than the running OS on a netbook but that is about it apart from showing others what is out there. So I would not use it for storing stuff - just internet mainly as they are basically mini SSD's with limited re-writes!