there is wikimatrix http://www.wikimatrix.org/index.php
But doesn't seem to list 'edit approval' as a feature to compare, unless its listed under some obscure name.
The German wikipedia (MediaWiki) is using a feature called 'Pending Changes', where unregistered user changes have to be reviewed. Therefore a host using MediaWiki may have a similar feature. http://en.citizendium.org/wiki/Wikipedia
Harry,
You probably want some sort of Word import facility in case you are sitting on a pile of documents that you want to convert/upload.
With 300 users, you'll have a mix of people who prefer WYSIWYG and no doubt the IT gang would use Markdown. The biggest thing with WYSIWYG is cross-browser cut-past screenshots -- make documenting as easy as possible.
Pages tend to lead you down a path of N-clicking before you get down to the information you need (nested pages of N depth). Some people prefer classic single document view -- just scroll to consume the contents.
Folders/Space/Collections will need to be augmented by tagging of some sort to help organize content -- no point typing up know-how if nobody knows it exists.
You always get teams that want to ring-fence their content so team, global and personal content visibility is important.
Feedback/actions tend to still rely on email tennis so look for something that handles the basic workflows to ease the burden on content owners.
You should add https://documize.com to your shortlist (started this to solve the docs+wiki problem).
Hope this helps you.
I used Wikidot when I was at University, but that's mainly because I was very familiar with it. I'm a volunteer community administrator there. It served my purposes well.
Feel free to PM me if you end up trying Wikidot, and need any assistance :)
Another solution I'd suggest, although not a wiki, would be OneNote. That's available on all devices now, including iOS and Android, and works well for the task.
I use one of my dokuwiki installation as a blog! Dokuwiki's blog plugin, along with the include and pagelist plugins should meet all of those requirements. You could use the include plugin, which allows you to transclude another wiki page, as a replacement for templates (I think there might also be a templates a la wikimedia plugin). You can also try any theme on a dokuwiki installation, despite how unflattering the initial install may look. Pretty simple!
Wikidot provides the option to create private wikis, including on their Free account. If you haven't created your wiki yet or it is still extremely new, that may be an option.
However, if it is an established wiki on another platform - please confirm what you are using. Is it MediaWiki, as maiki has assumed?
Disclaimer: I am a volunteer community administrator for Wikidot, so I may be biased towards it, but I can also give you some assistance if you end up using it.
Most of the subscribers in this subreddit are here because of an old bug in an app called Relay for reddit.
If you haven't already then you should post that somewhere actually MediaWiki related