Did you choose one yet?
It also comes down to budget if you are constrained by one. Zhou being the more economical choice and not a bad half-case.
I have Zhou (IIIf), Luigi/Leicatime (IIIf & M2), and original bottom half of EverReady case (M6) and like them each for their own characteristics.
I like them on the cameras for added bulk in handling, protection - to absorb those pesky bumps the camera might take as you move around or place down on a surface*, and to insulate against transfer of hand salts which may creep into the tiny crevices and camera skin.
Chris has some good points. Of course, if I was a working pro, I wouldn't do any of this 🙂. But like Rick, I shoot casually and don't burn through film.
I think Roger had a thread or article about this topic. There are also quite a few (heated) philosophical discussions on this topic on RFF... 😀
Good luck choosing.
*Pet peeve - camera for sale ads showing cameras placed on hard scratchy surfaces - concrete, granite, tile, etc. Arggg!