I work for a pretty large organisation (multiple office sites, multiple countries etc). Our intranet runs on sharepoint and every time I've had to edit a page or create a new page etc I find it frustrating as hell and don't get me started on permissions problems.
From the users perspective it is pretty handy. There are a heap of non technical people (HR, accountants, operators etc.) Being able to drag and drop spreadsheets from a Windows desktop into a sharepoint library is almost a killer feature makes it very easy for non technical people to collaborate on documents across multiple sites (provided the aforementioned permissions problems do not occur).
Our plant operators use it to upload overtime spreadsheets and share them between shifts, people use it to share powerpoint slide decks for meetings and upload the minutes afterwards etc.
I'm from the generation before we had Sharepoint back then we used Mapped network shares to move documents around (or emails - but we had 50mb limit imposed by exchange) - permissions issue were even worse.
We recently started using Facebook's "Workplace" which is basically a private facebook instance for our organisation. People are starting to use that instead of sharepoint - from what I've seen anyone can make a "group" in workplace and it is so much easier then setting up a sharepoint page.
Adoption is pretty slow but some teams are starting to use workplace groups rather than sharepoint for recurring meetings etc. So I'm hoping it will finally kill Sharepoint here.