Sharepoint is where perfectly good information goes to die.
I used SharePoint extensively and yes, it has it's issues. I didn't use it for any HTML cut-and-paste. All of the WISIG browser editors I've used mangle HTML. MS interacts with their RTF much better.
Anyhow, I used SharePoint to manage versioning and workflow for an endless number of software documentation artifacts. SharePoint does some really nice quasi-spreadsheet list management with pivots / views on any attribute. It was great for tracking product roadmaps with custom feature scoring (formulas to quantify request and success [risk] factors).
All of the "site" / "portal" security / search management features was mess. MS bought SharePoint and should have rewritten it from the ground up.