Share your experience!
Think about the choices outlined.
Each is clearly detailed with their respective characteristics based upon their design, and construction.
Then decide for yourself what is most important FOR YOU. 
Personally, I used my ZL without a case.
So I could feel the premium construction each and every time I handled the device.
Taking advantage of the grippy, textured back panel, designed to ensure a secure grip.
Without a case allowed my ZL to dissipate heat more effectively than using it in a case.
For sure, I was concerned about dropping it.
And I did accidently drop it a couple of times.
But the experience simply taught me to handle it with more care.
I miss my ZL more than the Z I am currently using. 