Zim has its good points, but the biggest problem I have with it is the inability to wrap lines shorter than the full monitor width. On a 13" laptop, it's usable; on a widescreen desktop monitor it just doesn't work. Other wikis like tiddlywiki, pmwiki, and dokuwiki are able to avoid this.
Certainly not had that problem myself but one of the reasons I use zim-wiki is because it supports displaying embedded pictures which for certain things is very useful.
I could shrink the window, but that's definitely not an optimal solution. It also means that I lose much of my screen width. That creates its own problems.
Here's a bug someone filed that hasn't even so much as gotten a response after nearly eight months:
